231018381 has 24 divisors (see below), whose sum is σ = 364684320. Its totient is φ = 139759200.

The previous prime is 231018377. The next prime is 231018413. The reversal of 231018381 is 183810132.

It is not a de Polignac number, because 231018381 - 2² = 231018377 is a prime.

It is a super-2 number, since 2×231018381² = 106738984719722322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231018311) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 63471 + ... + 67011.

It is an arithmetic number, because the mean of its divisors is an integer number (15195180).

Almost surely, 2^231018381 is an apocalyptic number.

It is an amenable number.

231018381 is a deficient number, since it is larger than the sum of its proper divisors (133665939).

231018381 is a wasteful number, since it uses less digits than its factorization.

231018381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4217 (or 4214 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 231018381 is about 15199.2888320474. The cubic root of 231018381 is about 613.5955179935.

The spelling of 231018381 in words is "two hundred thirty-one million, eighteen thousand, three hundred eighty-one".