14691621681 has 27 divisors (see below), whose sum is σ = 23332168587. Its totient is φ = 8901588960.

The previous prime is 14691621673. The next prime is 14691621713. The reversal of 14691621681 is 18612619641.

The square root of 14691621681 is 121209.

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

14691621681 is a `hidden beast` number, since 14 + 6 + 9 + 1 + 621 + 6 + 8 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 952031025 + 13739590656 = 30855^2 + 117216^2 .

It is not a de Polignac number, because 14691621681 - 2³ = 14691621673 is a prime.

It is a super-2 number, since 2×14691621681² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (14691621781) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 3998061 + ... + 4001733.

Almost surely, 2^14691621681 is an apocalyptic number.

14691621681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

14691621681 is the 121209-th square number.

14691621681 is the 60605-th centered octagonal number.

It is an amenable number.

14691621681 is a deficient number, since it is larger than the sum of its proper divisors (8640546906).

14691621681 is an frugal number, since it uses more digits than its factorization.

14691621681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7374 (or 3687 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The spelling of 14691621681 in words is "fourteen billion, six hundred ninety-one million, six hundred twenty-one thousand, six hundred eighty-one".