681559966 has 16 divisors (see below), whose sum is σ = 1086921504. Its totient is φ = 319812064.

The previous prime is 681559919. The next prime is 681559981. The reversal of 681559966 is 669955186.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137341 + ... + 142216.

It is an arithmetic number, because the mean of its divisors is an integer number (67932594).

Almost surely, 2^681559966 is an apocalyptic number.

681559966 is a deficient number, since it is larger than the sum of its proper divisors (405361538).

681559966 is a wasteful number, since it uses less digits than its factorization.

681559966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279635.

The product of its digits is 3499200, while the sum is 55.

The square root of 681559966 is about 26106.7034686496. The cubic root of 681559966 is about 880.0378625238.

The spelling of 681559966 in words is "six hundred eighty-one million, five hundred fifty-nine thousand, nine hundred sixty-six".