642633408 has 42 divisors (see below), whose sum is σ = 1841994284. Its totient is φ = 214210944.

The previous prime is 642633391. The next prime is 642633413. The reversal of 642633408 is 804336246.

It is a happy number.

642633408 is a `hidden beast` number, since 642 + 6 + 3 + 3 + 4 + 0 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 557266 + ... + 558417.

Almost surely, 2^642633408 is an apocalyptic number.

It is an amenable number.

642633408 is an abundant number, since it is smaller than the sum of its proper divisors (1199360876).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642633408 is a wasteful number, since it uses less digits than its factorization.

642633408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1115701 (or 1115688 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The square root of 642633408 is about 25350.2151470160. The cubic root of 642633408 is about 862.9542388662.

The spelling of 642633408 in words is "six hundred forty-two million, six hundred thirty-three thousand, four hundred eight".