642726920 has 32 divisors (see below), whose sum is σ = 1577603520. Its totient is φ = 233718720.

The previous prime is 642726899. The next prime is 642726923. The reversal of 642726920 is 29627246.

It is a happy number.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (642726923) 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, 729932 + ... + 730811.

It is an arithmetic number, because the mean of its divisors is an integer number (49300110).

Almost surely, 2^642726920 is an apocalyptic number.

It is an amenable number.

642726920 is an abundant number, since it is smaller than the sum of its proper divisors (934876600).

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

642726920 is a wasteful number, since it uses less digits than its factorization.

642726920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1460765 (or 1460761 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 38.

The square root of 642726920 is about 25352.0594824168. The cubic root of 642726920 is about 862.9960940732.

The spelling of 642726920 in words is "six hundred forty-two million, seven hundred twenty-six thousand, nine hundred twenty".