649637831 has 2 divisors, whose sum is σ = 649637832. Its totient is φ = 649637830.

The previous prime is 649637773. The next prime is 649637899. The reversal of 649637831 is 138736946.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-649637831 is a prime.

It is a super-2 number, since 2×649637831² = 844058622932769122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649697831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324818915 + 324818916.

It is an arithmetic number, because the mean of its divisors is an integer number (324818916).

Almost surely, 2^649637831 is an apocalyptic number.

649637831 is a deficient number, since it is larger than the sum of its proper divisors (1).

649637831 is an equidigital number, since it uses as much as digits as its factorization.

649637831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 47.

The square root of 649637831 is about 25487.9938598549. The cubic root of 649637831 is about 866.0781908609.

It can be divided in two parts, 64963 and 7831, that multiplied together give a triangular number (508725253 = T₃₁₈₉₇).

The spelling of 649637831 in words is "six hundred forty-nine million, six hundred thirty-seven thousand, eight hundred thirty-one".