231020172 has 18 divisors (see below), whose sum is σ = 583967748. Its totient is φ = 77006712.

The previous prime is 231020171. The next prime is 231020189. The reversal of 231020172 is 271020132.

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

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (231020171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3208578 + ... + 3208649.

Almost surely, 2^231020172 is an apocalyptic number.

It is an amenable number.

231020172 is an abundant number, since it is smaller than the sum of its proper divisors (352947576).

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

231020172 is a wasteful number, since it uses less digits than its factorization.

231020172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6417237 (or 6417232 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 231020172 is about 15199.3477491634. The cubic root of 231020172 is about 613.5971036491.

The spelling of 231020172 in words is "two hundred thirty-one million, twenty thousand, one hundred seventy-two".