231212520 has 384 divisors, whose sum is σ = 988416000. Its totient is φ = 45411840.

The previous prime is 231212441. The next prime is 231212521. The reversal of 231212520 is 25212132.

231212520 is a `hidden beast` number, since 23 + 121 + 2 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 231212493 and 231212502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231212521) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 526461 + ... + 526899.

It is an arithmetic number, because the mean of its divisors is an integer number (2574000).

Almost surely, 2^231212520 is an apocalyptic number.

231212520 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 231212520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (494208000).

231212520 is an abundant number, since it is smaller than the sum of its proper divisors (757203480).

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

231212520 is a wasteful number, since it uses less digits than its factorization.

231212520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493 (or 486 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 231212520 is about 15205.6739409998. The cubic root of 231212520 is about 613.7673505934.

Adding to 231212520 its reverse (25212132), we get a palindrome (256424652).

The spelling of 231212520 in words is "two hundred thirty-one million, two hundred twelve thousand, five hundred twenty".