231385220 has 48 divisors (see below), whose sum is σ = 532175616. Its totient is φ = 83808000.

The previous prime is 231385213. The next prime is 231385247. The reversal of 231385220 is 22583132.

It is a super-3 number, since 3×231385220³ (a number of 26 digits) contains 333 as substring.

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 231385220.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57680 + ... + 61560.

It is an arithmetic number, because the mean of its divisors is an integer number (11086992).

Almost surely, 2^231385220 is an apocalyptic number.

231385220 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 231385220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (266087808).

231385220 is an abundant number, since it is smaller than the sum of its proper divisors (300790396).

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

231385220 is a wasteful number, since it uses less digits than its factorization.

231385220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4172 (or 4170 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 231385220 is about 15211.3516822142. The cubic root of 231385220 is about 613.9201266937.

The spelling of 231385220 in words is "two hundred thirty-one million, three hundred eighty-five thousand, two hundred twenty".