231139240 has 32 divisors (see below), whose sum is σ = 524675880. Its totient is φ = 91635712.

The previous prime is 231139231. The next prime is 231139241. The reversal of 231139240 is 42931132.

It can be written as a sum of positive squares in 4 ways, for example, as 171138724 + 60000516 = 13082^2 + 7746^2 .

It is not an unprimeable number, because it can be changed into a prime (231139241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21049 + ... + 30088.

Almost surely, 2^231139240 is an apocalyptic number.

231139240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231139240 is an abundant number, since it is smaller than the sum of its proper divisors (293536640).

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

231139240 is a wasteful number, since it uses less digits than its factorization.

231139240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51261 (or 51257 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 231139240 is about 15203.2641232072. The cubic root of 231139240 is about 613.7025017062.

The spelling of 231139240 in words is "two hundred thirty-one million, one hundred thirty-nine thousand, two hundred forty".