647649842 has 16 divisors (see below), whose sum is σ = 1110707520. Its totient is φ = 277451568.

The previous prime is 647649823. The next prime is 647649851. The reversal of 647649842 is 248946746.

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, 32909 + ... + 48767.

It is an arithmetic number, because the mean of its divisors is an integer number (69419220).

Almost surely, 2^647649842 is an apocalyptic number.

647649842 is a deficient number, since it is larger than the sum of its proper divisors (463057678).

647649842 is a wasteful number, since it uses less digits than its factorization.

647649842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18785.

The product of its digits is 2322432, while the sum is 50.

The square root of 647649842 is about 25448.9654406618. The cubic root of 647649842 is about 865.1938452039.

The spelling of 647649842 in words is "six hundred forty-seven million, six hundred forty-nine thousand, eight hundred forty-two".