642706960 has 80 divisors (see below), whose sum is σ = 1720996992. Its totient is φ = 218649600.

The previous prime is 642706921. The next prime is 642706969. The reversal of 642706960 is 69607246.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is not an unprimeable number, because it can be changed into a prime (642706969) 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, 68980 + ... + 77740.

Almost surely, 2^642706960 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 642706960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (860498496).

642706960 is an abundant number, since it is smaller than the sum of its proper divisors (1078290032).

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

642706960 is a wasteful number, since it uses less digits than its factorization.

642706960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8912 (or 8906 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 40.

The square root of 642706960 is about 25351.6658229790. The cubic root of 642706960 is about 862.9871604812.

The spelling of 642706960 in words is "six hundred forty-two million, seven hundred six thousand, nine hundred sixty".