231515221002 has 128 divisors (see below), whose sum is σ = 537387540480. Its totient is φ = 65937062400.

The previous prime is 231515220997. The next prime is 231515221009. The reversal of 231515221002 is 200122515132.

It is not an unprimeable number, because it can be changed into a prime (231515221009) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7488877 + ... + 7519727.

It is an arithmetic number, because the mean of its divisors is an integer number (4198340160).

Almost surely, 2^231515221002 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231515221002, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (268693770240).

231515221002 is an abundant number, since it is smaller than the sum of its proper divisors (305872319478).

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

231515221002 is a wasteful number, since it uses less digits than its factorization.

231515221002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31028.

The product of its (nonzero) digits is 1200, while the sum is 24.

Adding to 231515221002 its reverse (200122515132), we get a palindrome (431637736134).

The spelling of 231515221002 in words is "two hundred thirty-one billion, five hundred fifteen million, two hundred twenty-one thousand, two".