649657565928 has 288 divisors, whose sum is σ = 2138328153000. Its totient is φ = 177438643200.

The previous prime is 649657565897. The next prime is 649657565939. The reversal of 649657565928 is 829565756946.

It is a happy number.

649657565928 is a `hidden beast` number, since 6 + 4 + 9 + 6 + 57 + 565 + 9 + 2 + 8 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 602489544804 + 47168021124 = 776202^2 + 217182^2 .

It is a Harshad number since it is a multiple of its sum of digits (72).

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 71 ways as a sum of consecutive naturals, for example, 10302078 + ... + 10364946.

Almost surely, 2^649657565928 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649657565928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1069164076500).

649657565928 is an abundant number, since it is smaller than the sum of its proper divisors (1488670587072).

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

649657565928 is a wasteful number, since it uses less digits than its factorization.

649657565928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63025 (or 63011 counting only the distinct ones).

The product of its digits is 979776000, while the sum is 72.

The spelling of 649657565928 in words is "six hundred forty-nine billion, six hundred fifty-seven million, five hundred sixty-five thousand, nine hundred twenty-eight".