231221250520 has 96 divisors (see below), whose sum is σ = 565150262400. Its totient is φ = 85100461056.

The previous prime is 231221250511. The next prime is 231221250529. The reversal of 231221250520 is 25052122132.

It is an interprime number because it is at equal distance from previous prime (231221250511) and next prime (231221250529).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231221250529) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2061241 + ... + 2170519.

It is an arithmetic number, because the mean of its divisors is an integer number (5886981900).

Almost surely, 2^231221250520 is an apocalyptic number.

231221250520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231221250520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (282575131200).

231221250520 is an abundant number, since it is smaller than the sum of its proper divisors (333929011880).

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

231221250520 is a wasteful number, since it uses less digits than its factorization.

231221250520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109629 (or 109612 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

Adding to 231221250520 its reverse (25052122132), we get a palindrome (256273372652).

The spelling of 231221250520 in words is "two hundred thirty-one billion, two hundred twenty-one million, two hundred fifty thousand, five hundred twenty".