681955659 has 64 divisors (see below), whose sum is σ = 1264680960. Its totient is φ = 352836000.

The previous prime is 681955649. The next prime is 681955679. The reversal of 681955659 is 956559186.

681955659 is a `hidden beast` number, since 6 + 81 + 9 + 556 + 5 + 9 = 666.

It is not a de Polignac number, because 681955659 - 2⁴ = 681955643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (681955609) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 687654 + ... + 688644.

It is an arithmetic number, because the mean of its divisors is an integer number (19760640).

Almost surely, 2^681955659 is an apocalyptic number.

681955659 is a deficient number, since it is larger than the sum of its proper divisors (582725301).

681955659 is a wasteful number, since it uses less digits than its factorization.

681955659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1349 (or 1343 counting only the distinct ones).

The product of its digits is 2916000, while the sum is 54.

The square root of 681955659 is about 26114.2807482802. The cubic root of 681955659 is about 880.2081373206.

The spelling of 681955659 in words is "six hundred eighty-one million, nine hundred fifty-five thousand, six hundred fifty-nine".