405544201012021 has 4 divisors (see below), whose sum is σ = 412192466602444. Its totient is φ = 398895935421600.

The previous prime is 405544201011979. The next prime is 405544201012037. The reversal of 405544201012021 is 120210102445504.

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 29363241713796 + 376180959298225 = 5418786^2 + 19395385^2 .

It is a cyclic number.

It is not a de Polignac number, because 405544201012021 - 2¹⁹ = 405544200487733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405544201012061) 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, 3324132795120 + ... + 3324132795241.

It is an arithmetic number, because the mean of its divisors is an integer number (103048116650611).

Almost surely, 2^{405544201012021} is an apocalyptic number.

It is an amenable number.

405544201012021 is a deficient number, since it is larger than the sum of its proper divisors (6648265590423).

405544201012021 is an equidigital number, since it uses as much as digits as its factorization.

405544201012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6648265590422.

The product of its (nonzero) digits is 12800, while the sum is 31.

Adding to 405544201012021 its reverse (120210102445504), we get a palindrome (525754303457525).

The spelling of 405544201012021 in words is "four hundred five trillion, five hundred forty-four billion, two hundred one million, twelve thousand, twenty-one".