649779988 has 36 divisors (see below), whose sum is σ = 1343266848. Its totient is φ = 272631840.

The previous prime is 649779983. The next prime is 649779997. The reversal of 649779988 is 889977946.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649779983) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36256 + ... + 51127.

It is an arithmetic number, because the mean of its divisors is an integer number (37312968).

Almost surely, 2^649779988 is an apocalyptic number.

It is an amenable number.

649779988 is an abundant number, since it is smaller than the sum of its proper divisors (693486860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

649779988 is a wasteful number, since it uses less digits than its factorization.

649779988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87424 (or 87409 counting only the distinct ones).

The product of its digits is 54867456, while the sum is 67.

The square root of 649779988 is about 25490.7824124722. The cubic root of 649779988 is about 866.1413594409.

The spelling of 649779988 in words is "six hundred forty-nine million, seven hundred seventy-nine thousand, nine hundred eighty-eight".