231213100 has 72 divisors (see below), whose sum is σ = 515123280. Its totient is φ = 90055680.

The previous prime is 231213077. The next prime is 231213113. The reversal of 231213100 is 1312132.

231213100 = 176² + 177² + ... + 887².

It is a super-2 number, since 2×231213100² = 106918995223220000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 738544 + ... + 738856.

It is an arithmetic number, because the mean of its divisors is an integer number (7154490).

Almost surely, 2^231213100 is an apocalyptic number.

231213100 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 231213100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (257561640).

231213100 is an abundant number, since it is smaller than the sum of its proper divisors (283910180).

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

231213100 is a wasteful number, since it uses less digits than its factorization.

231213100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 499 (or 492 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 231213100 is about 15205.6930128160. The cubic root of 231213100 is about 613.7678638078.

Adding to 231213100 its reverse (1312132), we get a palindrome (232525232).

The spelling of 231213100 in words is "two hundred thirty-one million, two hundred thirteen thousand, one hundred".