649984691 has 2 divisors, whose sum is σ = 649984692. Its totient is φ = 649984690.

The previous prime is 649984679. The next prime is 649984721. The reversal of 649984691 is 196489946.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 649984691 - 2¹⁸ = 649722547 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (649981691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324992345 + 324992346.

It is an arithmetic number, because the mean of its divisors is an integer number (324992346).

Almost surely, 2^649984691 is an apocalyptic number.

649984691 is a deficient number, since it is larger than the sum of its proper divisors (1).

649984691 is an equidigital number, since it uses as much as digits as its factorization.

649984691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3359232, while the sum is 56.

The square root of 649984691 is about 25494.7973320048. The cubic root of 649984691 is about 866.2323046442.

The spelling of 649984691 in words is "six hundred forty-nine million, nine hundred eighty-four thousand, six hundred ninety-one".