642739908 has 24 divisors (see below), whose sum is σ = 1503079200. Its totient is φ = 213767680.

The previous prime is 642739871. The next prime is 642739921. The reversal of 642739908 is 809937246.

It is a super-2 number, since 2×642739908² = 826229178671696928, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54258 + ... + 65033.

It is an arithmetic number, because the mean of its divisors is an integer number (62628300).

Almost surely, 2^642739908 is an apocalyptic number.

It is an amenable number.

642739908 is an abundant number, since it is smaller than the sum of its proper divisors (860339292).

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

642739908 is a wasteful number, since it uses less digits than its factorization.

642739908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119747 (or 119745 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 48.

The square root of 642739908 is about 25352.3156338824. The cubic root of 642739908 is about 863.0019070748.

The spelling of 642739908 in words is "six hundred forty-two million, seven hundred thirty-nine thousand, nine hundred eight".