231312221312 has 64 divisors (see below), whose sum is σ = 471911045760. Its totient is φ = 112876108800.

The previous prime is 231312221293. The next prime is 231312221317. The reversal of 231312221312 is 213122213132.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (231312221317) 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, 7144553 + ... + 7176855.

It is an arithmetic number, because the mean of its divisors is an integer number (7373610090).

Almost surely, 2^231312221312 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 231312221312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (235955522880).

231312221312 is an abundant number, since it is smaller than the sum of its proper divisors (240598824448).

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

231312221312 is a wasteful number, since it uses less digits than its factorization.

231312221312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33661 (or 33649 counting only the distinct ones).

The product of its digits is 864, while the sum is 23.

Adding to 231312221312 its reverse (213122213132), we get a palindrome (444434434444).

The spelling of 231312221312 in words is "two hundred thirty-one billion, three hundred twelve million, two hundred twenty-one thousand, three hundred twelve".