91985430681 has 63 divisors (see below), whose sum is σ = 141503908261. Its totient is φ = 59767737624.

The previous prime is 91985430653. The next prime is 91985430703. The reversal of 91985430681 is 18603458919.

The square root of 91985430681 is 303291.

It is a perfect power (a square), and thus also a powerful number.

91985430681 is a `hidden beast` number, since 9 + 1 + 98 + 543 + 0 + 6 + 8 + 1 = 666.

It is not a de Polignac number, because 91985430681 - 2⁷ = 91985430553 is a prime.

It is a super-2 number, since 2×91985430681² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91985430631) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 384876160 + ... + 384876398.

Almost surely, 2^91985430681 is an apocalyptic number.

91985430681 is the 303291-st square number.

91985430681 is the 151646-th centered octagonal number.

It is an amenable number.

91985430681 is a deficient number, since it is larger than the sum of its proper divisors (49518477580).

91985430681 is an frugal number, since it uses more digits than its factorization.

91985430681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 54.

The spelling of 91985430681 in words is "ninety-one billion, nine hundred eighty-five million, four hundred thirty thousand, six hundred eighty-one".