402664621 has 4 divisors (see below), whose sum is σ = 403137532. Its totient is φ = 402191712.

The previous prime is 402664607. The next prime is 402664627. The reversal of 402664621 is 126466204.

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 19053225 + 383611396 = 4365^2 + 19586^2 .

It is a cyclic number.

It is not a de Polignac number, because 402664621 - 2⁵ = 402664589 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 (402664627) 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, 235176 + ... + 236881.

It is an arithmetic number, because the mean of its divisors is an integer number (100784383).

Almost surely, 2^402664621 is an apocalyptic number.

It is an amenable number.

402664621 is a deficient number, since it is larger than the sum of its proper divisors (472911).

402664621 is an equidigital number, since it uses as much as digits as its factorization.

402664621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472910.

The product of its (nonzero) digits is 13824, while the sum is 31.

The square root of 402664621 is about 20066.5049522830. The cubic root of 402664621 is about 738.4387714271.

The spelling of 402664621 in words is "four hundred two million, six hundred sixty-four thousand, six hundred twenty-one".