402031521 has 12 divisors (see below), whose sum is σ = 614871972. Its totient is φ = 252254976.

The previous prime is 402031501. The next prime is 402031537. The reversal of 402031521 is 125130204.

It can be written as a sum of positive squares in 2 ways, for example, as 377913600 + 24117921 = 19440^2 + 4911^2 .

It is not a de Polignac number, because 402031521 - 2²² = 397837217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 402031494 and 402031503.

It is not an unprimeable number, because it can be changed into a prime (402031501) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1313676 + ... + 1313981.

It is an arithmetic number, because the mean of its divisors is an integer number (51239331).

Almost surely, 2^402031521 is an apocalyptic number.

It is an amenable number.

402031521 is a deficient number, since it is larger than the sum of its proper divisors (212840451).

402031521 is a wasteful number, since it uses less digits than its factorization.

402031521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2627680 (or 2627677 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 402031521 is about 20050.7237026497. The cubic root of 402031521 is about 738.0515585192.

Adding to 402031521 its reverse (125130204), we get a palindrome (527161725).

The spelling of 402031521 in words is "four hundred two million, thirty-one thousand, five hundred twenty-one".