231617961 has 45 divisors (see below), whose sum is σ = 369315111. Its totient is φ = 144641376.

The previous prime is 231617959. The next prime is 231617963. The reversal of 231617961 is 169716132.

The square root of 231617961 is 15219.

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

231617961 is a `hidden beast` number, since 2 + 31 + 617 + 9 + 6 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (231617959) and next prime (231617963).

It can be written as a sum of positive squares in only one way, i.e., 44475561 + 187142400 = 6669^2 + 13680^2 .

It is not a de Polignac number, because 231617961 - 2¹ = 231617959 is a prime.

It is not an unprimeable number, because it can be changed into a prime (231617963) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 2602405 + ... + 2602493.

Almost surely, 2^231617961 is an apocalyptic number.

231617961 is the 15219-th square number.

231617961 is the 7610-th centered octagonal number.

It is an amenable number.

231617961 is a deficient number, since it is larger than the sum of its proper divisors (137697150).

231617961 is an frugal number, since it uses more digits than its factorization.

231617961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228 (or 111 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The cubic root of 231617961 is about 614.1258968285.

Multiplying 231617961 by its sum of digits (36), we get a square (8338246596 = 91314²).

It can be divided in two parts, 23 and 1617961, that added together give a square (1617984 = 1272²).

The spelling of 231617961 in words is "two hundred thirty-one million, six hundred seventeen thousand, nine hundred sixty-one".