640712772 has 36 divisors (see below), whose sum is σ = 1850948736. Its totient is φ = 183060720.

The previous prime is 640712749. The next prime is 640712797. The reversal of 640712772 is 277217046.

It is a happy number.

640712772 is a `hidden beast` number, since 640 + 7 + 1 + 2 + 7 + 7 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1271004 + ... + 1271507.

Almost surely, 2^640712772 is an apocalyptic number.

It is an amenable number.

640712772 is an abundant number, since it is smaller than the sum of its proper divisors (1210235964).

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

640712772 is a wasteful number, since it uses less digits than its factorization.

640712772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2542528 (or 2542523 counting only the distinct ones).

The product of its (nonzero) digits is 32928, while the sum is 36.

The square root of 640712772 is about 25312.3047548026. The cubic root of 640712772 is about 862.0936783041.

The spelling of 640712772 in words is "six hundred forty million, seven hundred twelve thousand, seven hundred seventy-two".