646663740650 has 12 divisors (see below), whose sum is σ = 1202794557702. Its totient is φ = 258665496240.

The previous prime is 646663740629. The next prime is 646663740713. The reversal of 646663740650 is 56047366646.

It can be written as a sum of positive squares in 3 ways, for example, as 570401052001 + 76262688649 = 755249^2 + 276157^2 .

It is a junction number, because it is equal to n+sod(n) for n = 646663740592 and 646663740601.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6466637357 + ... + 6466637456.

Almost surely, 2^646663740650 is an apocalyptic number.

646663740650 is a deficient number, since it is larger than the sum of its proper divisors (556130817052).

646663740650 is a wasteful number, since it uses less digits than its factorization.

646663740650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12933274825 (or 12933274820 counting only the distinct ones).

The product of its (nonzero) digits is 13063680, while the sum is 53.

The spelling of 646663740650 in words is "six hundred forty-six billion, six hundred sixty-three million, seven hundred forty thousand, six hundred fifty".