647311631 has 8 divisors (see below), whose sum is σ = 663580080. Its totient is φ = 631193472.

The previous prime is 647311619. The next prime is 647311657. The reversal of 647311631 is 136113746.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647311631 is a prime.

It is a super-2 number, since 2×647311631² = 838024695255760322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647311831) 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, 28826 + ... + 46103.

It is an arithmetic number, because the mean of its divisors is an integer number (82947510).

Almost surely, 2^647311631 is an apocalyptic number.

647311631 is a deficient number, since it is larger than the sum of its proper divisors (16268449).

647311631 is a wasteful number, since it uses less digits than its factorization.

647311631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75145.

The product of its digits is 9072, while the sum is 32.

The square root of 647311631 is about 25442.3196859091. The cubic root of 647311631 is about 865.0432138968.

The spelling of 647311631 in words is "six hundred forty-seven million, three hundred eleven thousand, six hundred thirty-one".