649631 has 2 divisors, whose sum is σ = 649632. Its totient is φ = 649630.

The previous prime is 649619. The next prime is 649633. The reversal of 649631 is 136946.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 649631 - 2⁶ = 649567 is a prime.

It is a super-2 number, since 2×649631² = 844040872322, which contains 22 as substring.

Together with 649633, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 649594 and 649603.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324815 + 324816.

It is an arithmetic number, because the mean of its divisors is an integer number (324816).

2⁶⁴⁹⁶³¹ is an apocalyptic number.

649631 is a deficient number, since it is larger than the sum of its proper divisors (1).

649631 is an equidigital number, since it uses as much as digits as its factorization.

649631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 29.

The square root of 649631 is about 805.9968982571. The cubic root of 649631 is about 86.6075155220.

The spelling of 649631 in words is "six hundred forty-nine thousand, six hundred thirty-one".