400054021 has 4 divisors (see below), whose sum is σ = 404549100. Its totient is φ = 395558944.

The previous prime is 400054009. The next prime is 400054033. The reversal of 400054021 is 120450004.

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

It is an interprime number because it is at equal distance from previous prime (400054009) and next prime (400054033).

It can be written as a sum of positive squares in 2 ways, for example, as 46049796 + 354004225 = 6786^2 + 18815^2 .

It is a cyclic number.

It is not a de Polignac number, because 400054021 - 2¹³ = 400045829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 400053986 and 400054004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400054051) 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, 2247406 + ... + 2247583.

It is an arithmetic number, because the mean of its divisors is an integer number (101137275).

Almost surely, 2^400054021 is an apocalyptic number.

It is an amenable number.

400054021 is a deficient number, since it is larger than the sum of its proper divisors (4495079).

400054021 is an equidigital number, since it uses as much as digits as its factorization.

400054021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4495078.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 400054021 is about 20001.3504794051. The cubic root of 400054021 is about 736.8394674126.

The spelling of 400054021 in words is "four hundred million, fifty-four thousand, twenty-one".