21531042031312 has 20 divisors (see below), whose sum is σ = 45508793384736. Its totient is φ = 9786837286880.

The previous prime is 21531042031259. The next prime is 21531042031381. The reversal of 21531042031312 is 21313024013512.

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, 61167732868 + ... + 61167733219.

Almost surely, 2^{21531042031312} is an apocalyptic number.

21531042031312 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21531042031312 is an abundant number, since it is smaller than the sum of its proper divisors (23977751353424).

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

21531042031312 is a wasteful number, since it uses less digits than its factorization.

21531042031312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122335466106 (or 122335466100 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

Adding to 21531042031312 its reverse (21313024013512), we get a palindrome (42844066044824).

The spelling of 21531042031312 in words is "twenty-one trillion, five hundred thirty-one billion, forty-two million, thirty-one thousand, three hundred twelve".