21474264681 has 9 divisors (see below), whose sum is σ = 31019017341. Its totient is φ = 14315883372.

The previous prime is 21474264667. The next prime is 21474264689. The reversal of 21474264681 is 18646247412.

The square root of 21474264681 is 146541.

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

21474264681 is a `hidden beast` number, since 2 + 147 + 42 + 6 + 468 + 1 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 21474264681 - 2⁵ = 21474264649 is a prime.

It is a super-2 number, since 2×21474264681² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21474264689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 415200 + ... + 464046.

Almost surely, 2^21474264681 is an apocalyptic number.

21474264681 is the 146541-st square number.

21474264681 is the 73271-st centered octagonal number.

It is an amenable number.

21474264681 is a deficient number, since it is larger than the sum of its proper divisors (9544752660).

21474264681 is an frugal number, since it uses more digits than its factorization.

21474264681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97700 (or 48850 counting only the distinct ones).

The product of its digits is 516096, while the sum is 45.

The spelling of 21474264681 in words is "twenty-one billion, four hundred seventy-four million, two hundred sixty-four thousand, six hundred eighty-one".