231521280 has 88 divisors (see below), whose sum is σ = 740555472. Its totient is φ = 61734912.

The previous prime is 231521221. The next prime is 231521281. The reversal of 231521280 is 82125132.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 231521280.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231521281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7824 + ... + 22896.

Almost surely, 2^231521280 is an apocalyptic number.

231521280 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 231521280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (370277736).

231521280 is an abundant number, since it is smaller than the sum of its proper divisors (509034192).

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

231521280 is a wasteful number, since it uses less digits than its factorization.

231521280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15101 (or 15083 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 231521280 is about 15215.8233428231. The cubic root of 231521280 is about 614.0404363159.

The spelling of 231521280 in words is "two hundred thirty-one million, five hundred twenty-one thousand, two hundred eighty".