231978494772 has 18 divisors (see below), whose sum is σ = 586390084098. Its totient is φ = 77326164912.

The previous prime is 231978494771. The next prime is 231978494773. The reversal of 231978494772 is 277494879132.

231978494772 is a `hidden beast` number, since 2 + 3 + 1 + 9 + 78 + 494 + 7 + 72 = 666.

It is an interprime number because it is at equal distance from previous prime (231978494771) and next prime (231978494773).

It can be written as a sum of positive squares in only one way, i.e., 205502648976 + 26475845796 = 453324^2 + 162714^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231978494771) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3221923503 + ... + 3221923574.

Almost surely, 2^231978494772 is an apocalyptic number.

It is an amenable number.

231978494772 is an abundant number, since it is smaller than the sum of its proper divisors (354411589326).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

231978494772 is a wasteful number, since it uses less digits than its factorization.

231978494772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6443847087 (or 6443847082 counting only the distinct ones).

The product of its digits is 42674688, while the sum is 63.

The spelling of 231978494772 in words is "two hundred thirty-one billion, nine hundred seventy-eight million, four hundred ninety-four thousand, seven hundred seventy-two".