649821788 has 36 divisors (see below), whose sum is σ = 1428541296. Its totient is φ = 253176000.

The previous prime is 649821761. The next prime is 649821797. The reversal of 649821788 is 887128946.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 92513 + ... + 99288.

Almost surely, 2^649821788 is an apocalyptic number.

It is an amenable number.

649821788 is an abundant number, since it is smaller than the sum of its proper divisors (778719508).

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

649821788 is a wasteful number, since it uses less digits than its factorization.

649821788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191834 (or 191821 counting only the distinct ones).

The product of its digits is 1548288, while the sum is 53.

The square root of 649821788 is about 25491.6023035038. The cubic root of 649821788 is about 866.1599318466.

The spelling of 649821788 in words is "six hundred forty-nine million, eight hundred twenty-one thousand, seven hundred eighty-eight".