21215131144320 has 256 divisors, whose sum is σ = 67938185606400. Its totient is φ = 5631033655296.

The previous prime is 21215131144261. The next prime is 21215131144369. The reversal of 21215131144320 is 2344113151212.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2759867517 + ... + 2759875203.

It is an arithmetic number, because the mean of its divisors is an integer number (265383537525).

Almost surely, 2^{21215131144320} is an apocalyptic number.

21215131144320 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 21215131144320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33969092803200).

21215131144320 is an abundant number, since it is smaller than the sum of its proper divisors (46723054462080).

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

21215131144320 is a wasteful number, since it uses less digits than its factorization.

21215131144320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14215 (or 14203 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

Adding to 21215131144320 its reverse (2344113151212), we get a palindrome (23559244295532).

The spelling of 21215131144320 in words is "twenty-one trillion, two hundred fifteen billion, one hundred thirty-one million, one hundred forty-four thousand, three hundred twenty".