642935920 has 120 divisors (see below), whose sum is σ = 1740169872. Its totient is φ = 219985920.

The previous prime is 642935899. The next prime is 642935933. The reversal of 642935920 is 29539246.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 162607 + ... + 166513.

Almost surely, 2^642935920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642935920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (870084936).

642935920 is an abundant number, since it is smaller than the sum of its proper divisors (1097233952).

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

642935920 is a wasteful number, since it uses less digits than its factorization.

642935920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3959 (or 3942 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 40.

The square root of 642935920 is about 25356.1811004733. The cubic root of 642935920 is about 863.0896260909.

The spelling of 642935920 in words is "six hundred forty-two million, nine hundred thirty-five thousand, nine hundred twenty".