647238913 has 4 divisors (see below), whose sum is σ = 650306608. Its totient is φ = 644171220.

The previous prime is 647238901. The next prime is 647238923. The reversal of 647238913 is 319832746.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 647238913 - 2¹⁷ = 647107841 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 647238913.

It is not an unprimeable number, because it can be changed into a prime (647238923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1533531 + ... + 1533952.

It is an arithmetic number, because the mean of its divisors is an integer number (162576652).

Almost surely, 2^647238913 is an apocalyptic number.

It is an amenable number.

647238913 is a deficient number, since it is larger than the sum of its proper divisors (3067695).

647238913 is a wasteful number, since it uses less digits than its factorization.

647238913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3067694.

The product of its digits is 217728, while the sum is 43.

The square root of 647238913 is about 25440.8905701039. The cubic root of 647238913 is about 865.0108201393.

The spelling of 647238913 in words is "six hundred forty-seven million, two hundred thirty-eight thousand, nine hundred thirteen".