649677791 has 16 divisors (see below), whose sum is σ = 747512064. Its totient is φ = 553115904.

The previous prime is 649677781. The next prime is 649677817. The reversal of 649677791 is 197776946.

It is a cyclic number.

It is not a de Polignac number, because 649677791 - 2⁶ = 649677727 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649677781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1153676 + ... + 1154238.

It is an arithmetic number, because the mean of its divisors is an integer number (46719504).

Almost surely, 2^649677791 is an apocalyptic number.

649677791 is a deficient number, since it is larger than the sum of its proper divisors (97834273).

649677791 is a wasteful number, since it uses less digits than its factorization.

649677791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1390.

The product of its digits is 4000752, while the sum is 56.

The square root of 649677791 is about 25488.7777462945. Note that the first 4 decimals coincide. The cubic root of 649677791 is about 866.0959483320.

The spelling of 649677791 in words is "six hundred forty-nine million, six hundred seventy-seven thousand, seven hundred ninety-one".