647631 has 12 divisors (see below), whose sum is σ = 942552. Its totient is φ = 428496.

The previous prime is 647627. The next prime is 647641. The reversal of 647631 is 136746.

It is not a de Polignac number, because 647631 - 2² = 647627 is a prime.

It is a super-2 number, since 2×647631² = 838851824322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 647595 and 647604.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647631.

It is not an unprimeable number, because it can be changed into a prime (647641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1885 + ... + 2201.

It is an arithmetic number, because the mean of its divisors is an integer number (78546).

2⁶⁴⁷⁶³¹ is an apocalyptic number.

647631 is a deficient number, since it is larger than the sum of its proper divisors (294921).

647631 is a wasteful number, since it uses less digits than its factorization.

647631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550 (or 547 counting only the distinct ones).

The product of its digits is 3024, while the sum is 27.

The square root of 647631 is about 804.7552422942. The cubic root of 647631 is about 86.5185454795.

The spelling of 647631 in words is "six hundred forty-seven thousand, six hundred thirty-one".