400506553352021 has 4 divisors (see below), whose sum is σ = 410275005872844. Its totient is φ = 390738100831200.

The previous prime is 400506553351937. The next prime is 400506553352033. The reversal of 400506553352021 is 120253355605004.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9780724582225 + 390725828769796 = 3127415^2 + 19766786^2 .

It is a cyclic number.

It is not a de Polignac number, because 400506553352021 - 2²² = 400506549157717 is a prime.

It is a super-2 number, since 2×400506553352021² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 9768452520781 = 400506553352021 / (4 + 0 + 0 + 5 + 0 + 6 + 5 + 5 + 3 + 3 + 5 + 2 + 0 + 2 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 400506553352021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400506553352051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4884226260350 + ... + 4884226260431.

It is an arithmetic number, because the mean of its divisors is an integer number (102568751468211).

Almost surely, 2^{400506553352021} is an apocalyptic number.

400506553352021 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

400506553352021 is a deficient number, since it is larger than the sum of its proper divisors (9768452520823).

400506553352021 is an equidigital number, since it uses as much as digits as its factorization.

400506553352021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9768452520822.

The product of its (nonzero) digits is 540000, while the sum is 41.

The spelling of 400506553352021 in words is "four hundred trillion, five hundred six billion, five hundred fifty-three million, three hundred fifty-two thousand, twenty-one".