21531422231420 has 48 divisors (see below), whose sum is σ = 45251839080000. Its totient is φ = 8605740848640.

The previous prime is 21531422231411. The next prime is 21531422231447. The reversal of 21531422231420 is 2413222413512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 518196806 + ... + 518238354.

It is an arithmetic number, because the mean of its divisors is an integer number (942746647500).

Almost surely, 2^{21531422231420} is an apocalyptic number.

21531422231420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21531422231420 is an abundant number, since it is smaller than the sum of its proper divisors (23720416848580).

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

21531422231420 is a wasteful number, since it uses less digits than its factorization.

21531422231420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61478 (or 61476 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 32.

Adding to 21531422231420 its reverse (2413222413512), we get a palindrome (23944644644932).

The spelling of 21531422231420 in words is "twenty-one trillion, five hundred thirty-one billion, four hundred twenty-two million, two hundred thirty-one thousand, four hundred twenty".