642994956 has 24 divisors (see below), whose sum is σ = 1667024240. Its totient is φ = 214331616.

The previous prime is 642994951. The next prime is 642994999. The reversal of 642994956 is 659499246.

It is a happy number.

642994956 is a `hidden beast` number, since 64 + 2 + 99 + 495 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (642994951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2976721 + ... + 2976936.

Almost surely, 2^642994956 is an apocalyptic number.

It is an amenable number.

642994956 is an abundant number, since it is smaller than the sum of its proper divisors (1024029284).

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

642994956 is a wasteful number, since it uses less digits than its factorization.

642994956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5953670 (or 5953662 counting only the distinct ones).

The product of its digits is 4199040, while the sum is 54.

The square root of 642994956 is about 25357.3452080457. The cubic root of 642994956 is about 863.1160423055.

The spelling of 642994956 in words is "six hundred forty-two million, nine hundred ninety-four thousand, nine hundred fifty-six".