231217812 has 108 divisors (see below), whose sum is σ = 692424096. Its totient is φ = 63725760.

The previous prime is 231217801. The next prime is 231217823. The reversal of 231217812 is 218712132.

It is an interprime number because it is at equal distance from previous prime (231217801) and next prime (231217823).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 211387 + ... + 212477.

Almost surely, 2^231217812 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231217812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (346212048).

231217812 is an abundant number, since it is smaller than the sum of its proper divisors (461206284).

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

231217812 is a wasteful number, since it uses less digits than its factorization.

231217812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1166 (or 1132 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 231217812 is about 15205.8479539945. The cubic root of 231217812 is about 613.7720332004.

Adding to 231217812 its reverse (218712132), we get a palindrome (449929944).

The spelling of 231217812 in words is "two hundred thirty-one million, two hundred seventeen thousand, eight hundred twelve".