231690018 has 32 divisors (see below), whose sum is σ = 535965696. Its totient is φ = 65398608.

The previous prime is 231690013. The next prime is 231690023. The reversal of 231690018 is 810096132.

It is an interprime number because it is at equal distance from previous prime (231690013) and next prime (231690023).

It is not an unprimeable number, because it can be changed into a prime (231690013) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29746 + ... + 36717.

It is an arithmetic number, because the mean of its divisors is an integer number (16748928).

Almost surely, 2^231690018 is an apocalyptic number.

231690018 is an abundant number, since it is smaller than the sum of its proper divisors (304275678).

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

231690018 is a wasteful number, since it uses less digits than its factorization.

231690018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66558.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 231690018 is about 15221.3671527889. The cubic root of 231690018 is about 614.1895756575.

It can be divided in two parts, 23 and 1690018, that added together give a triangular number (1690041 = T₁₈₃₈).

The spelling of 231690018 in words is "two hundred thirty-one million, six hundred ninety thousand, eighteen".