642657960 has 96 divisors (see below), whose sum is σ = 2387024640. Its totient is φ = 146892672.

The previous prime is 642657949. The next prime is 642657971. The reversal of 642657960 is 69756246.

It is an interprime number because it is at equal distance from previous prime (642657949) and next prime (642657971).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 124992 + ... + 130031.

It is an arithmetic number, because the mean of its divisors is an integer number (24864840).

Almost surely, 2^642657960 is an apocalyptic number.

642657960 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

642657960 is an abundant number, since it is smaller than the sum of its proper divisors (1744366680).

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

642657960 is a wasteful number, since it uses less digits than its factorization.

642657960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255047 (or 255040 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 642657960 is about 25350.6993986359. The cubic root of 642657960 is about 862.9652285339.

The spelling of 642657960 in words is "six hundred forty-two million, six hundred fifty-seven thousand, nine hundred sixty".