642457920 has 112 divisors (see below), whose sum is σ = 2196754560. Its totient is φ = 158140416.

The previous prime is 642457901. The next prime is 642457927. The reversal of 642457920 is 29754246.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642457927) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13260 + ... + 38219.

It is an arithmetic number, because the mean of its divisors is an integer number (19613880).

Almost surely, 2^642457920 is an apocalyptic number.

642457920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

642457920 is an abundant number, since it is smaller than the sum of its proper divisors (1554296640).

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

642457920 is a wasteful number, since it uses less digits than its factorization.

642457920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51512 (or 51502 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 39.

The square root of 642457920 is about 25346.7536382867. The cubic root of 642457920 is about 862.8756809106.

The spelling of 642457920 in words is "six hundred forty-two million, four hundred fifty-seven thousand, nine hundred twenty".