231562101681 has 9 divisors (see below), whose sum is σ = 334480676569. Its totient is φ = 154373772036.

The previous prime is 231562101619. The next prime is 231562101713. The reversal of 231562101681 is 186101265132.

The square root of 231562101681 is 481209.

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

231562101681 is a `hidden beast` number, since 2 + 3 + 1 + 562 + 1 + 0 + 16 + 81 = 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 231562101681 - 2¹⁷ = 231561970609 is a prime.

It is a super-2 number, since 2×231562101681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231562101611) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1363426 + ... + 1523828.

Almost surely, 2^231562101681 is an apocalyptic number.

231562101681 is the 481209-th square number.

231562101681 is the 240605-th centered octagonal number.

It is an amenable number.

231562101681 is a deficient number, since it is larger than the sum of its proper divisors (102918574888).

231562101681 is an frugal number, since it uses more digits than its factorization.

231562101681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320812 (or 160406 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

Multiplying 231562101681 by its sum of digits (36), we get a square (8336235660516 = 2887254²).

The spelling of 231562101681 in words is "two hundred thirty-one billion, five hundred sixty-two million, one hundred one thousand, six hundred eighty-one".