215123431220 has 12 divisors (see below), whose sum is σ = 451759205604. Its totient is φ = 86049372480.

The previous prime is 215123431147. The next prime is 215123431231. The reversal of 215123431220 is 22134321512.

It can be written as a sum of positive squares in 2 ways, for example, as 77414158756 + 137709272464 = 278234^2 + 371092^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 215123431220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5378085761 + ... + 5378085800.

It is an arithmetic number, because the mean of its divisors is an integer number (37646600467).

Almost surely, 2^215123431220 is an apocalyptic number.

215123431220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215123431220 is an abundant number, since it is smaller than the sum of its proper divisors (236635774384).

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

215123431220 is a wasteful number, since it uses less digits than its factorization.

215123431220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10756171570 (or 10756171568 counting only the distinct ones).

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

Adding to 215123431220 its reverse (22134321512), we get a palindrome (237257752732).

The spelling of 215123431220 in words is "two hundred fifteen billion, one hundred twenty-three million, four hundred thirty-one thousand, two hundred twenty".