647923947 has 8 divisors (see below), whose sum is σ = 942434880. Its totient is φ = 392681160.

The previous prime is 647923933. The next prime is 647923949. The reversal of 647923947 is 749329746.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 647923947 - 2⁴ = 647923931 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 647923947.

It is not an unprimeable number, because it can be changed into a prime (647923949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9816997 + ... + 9817062.

It is an arithmetic number, because the mean of its divisors is an integer number (117804360).

Almost surely, 2^647923947 is an apocalyptic number.

647923947 is a deficient number, since it is larger than the sum of its proper divisors (294510933).

647923947 is a wasteful number, since it uses less digits than its factorization.

647923947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19634073.

The product of its digits is 2286144, while the sum is 51.

The square root of 647923947 is about 25454.3502568814. The cubic root of 647923947 is about 865.3158867221.

The spelling of 647923947 in words is "six hundred forty-seven million, nine hundred twenty-three thousand, nine hundred forty-seven".