681517650664 has 16 divisors (see below), whose sum is σ = 1319066421120. Its totient is φ = 329766605040.

The previous prime is 681517650637. The next prime is 681517650679. The reversal of 681517650664 is 466056715186.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1374027274 + ... + 1374027769.

It is an arithmetic number, because the mean of its divisors is an integer number (82441651320).

Almost surely, 2^681517650664 is an apocalyptic number.

It is an amenable number.

681517650664 is a deficient number, since it is larger than the sum of its proper divisors (637548770456).

681517650664 is a wasteful number, since it uses less digits than its factorization.

681517650664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2748055080 (or 2748055076 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 55.

The spelling of 681517650664 in words is "six hundred eighty-one billion, five hundred seventeen million, six hundred fifty thousand, six hundred sixty-four".