231560221640 has 48 divisors (see below), whose sum is σ = 572680973340. Its totient is φ = 84203715200.

The previous prime is 231560221601. The next prime is 231560221649. The reversal of 231560221640 is 46122065132.

It can be written as a sum of positive squares in 2 ways, for example, as 206768459524 + 24791762116 = 454718^2 + 157454^2 .

It is a junction number, because it is equal to n+sod(n) for n = 231560221597 and 231560221606.

It is not an unprimeable number, because it can be changed into a prime (231560221649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23916671 + ... + 23926350.

Almost surely, 2^231560221640 is an apocalyptic number.

231560221640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231560221640 is an abundant number, since it is smaller than the sum of its proper divisors (341120751700).

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

231560221640 is a wasteful number, since it uses less digits than its factorization.

231560221640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47843054 (or 47843039 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

Adding to 231560221640 its reverse (46122065132), we get a palindrome (277682286772).

The spelling of 231560221640 in words is "two hundred thirty-one billion, five hundred sixty million, two hundred twenty-one thousand, six hundred forty".