402663521 has 16 divisors (see below), whose sum is σ = 449789760. Its totient is φ = 357913920.

The previous prime is 402663517. The next prime is 402663529. The reversal of 402663521 is 125366204.

It is not a de Polignac number, because 402663521 - 2² = 402663517 is a prime.

It is a super-2 number, since 2×402663521² = 324275822288234882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (402663529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 165806 + ... + 168216.

It is an arithmetic number, because the mean of its divisors is an integer number (28111860).

Almost surely, 2^402663521 is an apocalyptic number.

It is an amenable number.

402663521 is a deficient number, since it is larger than the sum of its proper divisors (47126239).

402663521 is a wasteful number, since it uses less digits than its factorization.

402663521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2896.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 402663521 is about 20066.4775434056. The cubic root of 402663521 is about 738.4380990037.

The spelling of 402663521 in words is "four hundred two million, six hundred sixty-three thousand, five hundred twenty-one".