231115640 has 32 divisors (see below), whose sum is σ = 594298080. Its totient is φ = 79239552.

The previous prime is 231115631. The next prime is 231115657. The reversal of 231115640 is 46511132.

231115640 = 5743² + 5744² + ... + 5749².

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 412427 + ... + 412986.

It is an arithmetic number, because the mean of its divisors is an integer number (18571815).

Almost surely, 2^231115640 is an apocalyptic number.

231115640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231115640 is an abundant number, since it is smaller than the sum of its proper divisors (363182440).

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

231115640 is a wasteful number, since it uses less digits than its factorization.

231115640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825431 (or 825427 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 231115640 is about 15202.4879542791. The cubic root of 231115640 is about 613.6816140485.

Adding to 231115640 its reverse (46511132), we get a palindrome (277626772).

The spelling of 231115640 in words is "two hundred thirty-one million, one hundred fifteen thousand, six hundred forty".