647929866 has 16 divisors (see below), whose sum is σ = 1330883424. Its totient is φ = 210139344.

The previous prime is 647929837. The next prime is 647929897. The reversal of 647929866 is 668929746.

It is a super-2 number, since 2×647929866² = 839626222509555912, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1459080 + ... + 1459523.

It is an arithmetic number, because the mean of its divisors is an integer number (83180214).

Almost surely, 2^647929866 is an apocalyptic number.

647929866 is an abundant number, since it is smaller than the sum of its proper divisors (682953558).

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

647929866 is a wasteful number, since it uses less digits than its factorization.

647929866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2918645.

The product of its digits is 7838208, while the sum is 57.

The square root of 647929866 is about 25454.4665235789. The cubic root of 647929866 is about 865.3185216965.

The spelling of 647929866 in words is "six hundred forty-seven million, nine hundred twenty-nine thousand, eight hundred sixty-six".