649911887 has 4 divisors (see below), whose sum is σ = 688142016. Its totient is φ = 611681760.

The previous prime is 649911883. The next prime is 649911893. The reversal of 649911887 is 788119946.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 649911887 - 2² = 649911883 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 (649911883) 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 3 ways as a sum of consecutive naturals, for example, 19115039 + ... + 19115072.

It is an arithmetic number, because the mean of its divisors is an integer number (172035504).

Almost surely, 2^649911887 is an apocalyptic number.

649911887 is a deficient number, since it is larger than the sum of its proper divisors (38230129).

649911887 is a wasteful number, since it uses less digits than its factorization.

649911887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38230128.

The product of its digits is 870912, while the sum is 53.

The square root of 649911887 is about 25493.3694712959. The cubic root of 649911887 is about 866.1999615586.

The spelling of 649911887 in words is "six hundred forty-nine million, nine hundred eleven thousand, eight hundred eighty-seven".