21131431212440 has 16 divisors (see below), whose sum is σ = 47545720228080. Its totient is φ = 8452572484960.

The previous prime is 21131431212371. The next prime is 21131431212467. The reversal of 21131431212440 is 4421213413112.

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, 264142890116 + ... + 264142890195.

It is an arithmetic number, because the mean of its divisors is an integer number (2971607514255).

Almost surely, 2^{21131431212440} is an apocalyptic number.

21131431212440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21131431212440 is an abundant number, since it is smaller than the sum of its proper divisors (26414289015640).

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

21131431212440 is a wasteful number, since it uses less digits than its factorization.

21131431212440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528285780322 (or 528285780318 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

Adding to 21131431212440 its reverse (4421213413112), we get a palindrome (25552644625552).

The spelling of 21131431212440 in words is "twenty-one trillion, one hundred thirty-one billion, four hundred thirty-one million, two hundred twelve thousand, four hundred forty".