231220140 has 24 divisors (see below), whose sum is σ = 647416560. Its totient is φ = 61658688.

The previous prime is 231220097. The next prime is 231220153. The reversal of 231220140 is 41022132.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1926775 + ... + 1926894.

It is an arithmetic number, because the mean of its divisors is an integer number (26975690).

Almost surely, 2^231220140 is an apocalyptic number.

231220140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231220140 is an abundant number, since it is smaller than the sum of its proper divisors (416196420).

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

231220140 is a wasteful number, since it uses less digits than its factorization.

231220140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3853681 (or 3853679 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 231220140 is about 15205.9245032980. The cubic root of 231220140 is about 613.7740931000.

Adding to 231220140 its reverse (41022132), we get a palindrome (272242272).

The spelling of 231220140 in words is "two hundred thirty-one million, two hundred twenty thousand, one hundred forty".