649971656 has 16 divisors (see below), whose sum is σ = 1220933040. Its totient is φ = 324389520.

The previous prime is 649971643. The next prime is 649971661. The reversal of 649971656 is 656179946.

It is a junction number, because it is equal to n+sod(n) for n = 649971598 and 649971607.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69890 + ... + 78641.

It is an arithmetic number, because the mean of its divisors is an integer number (76308315).

Almost surely, 2^649971656 is an apocalyptic number.

It is an amenable number.

649971656 is a deficient number, since it is larger than the sum of its proper divisors (570961384).

649971656 is a wasteful number, since it uses less digits than its factorization.

649971656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149084 (or 149080 counting only the distinct ones).

The product of its digits is 2449440, while the sum is 53.

The square root of 649971656 is about 25494.5416903305. The cubic root of 649971656 is about 866.2265140393.

The spelling of 649971656 in words is "six hundred forty-nine million, nine hundred seventy-one thousand, six hundred fifty-six".