21132431340 has 48 divisors (see below), whose sum is σ = 59361120000. Its totient is φ = 5617190080.

The previous prime is 21132431339. The next prime is 21132431357. The reversal of 21132431340 is 4313423112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21132431340.

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, 547590 + ... + 584909.

It is an arithmetic number, because the mean of its divisors is an integer number (1236690000).

Almost surely, 2^21132431340 is an apocalyptic number.

21132431340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21132431340 is an abundant number, since it is smaller than the sum of its proper divisors (38228688660).

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

21132431340 is a wasteful number, since it uses less digits than its factorization.

21132431340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132822 (or 1132820 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 21132431340 its reverse (4313423112), we get a palindrome (25445854452).

The spelling of 21132431340 in words is "twenty-one billion, one hundred thirty-two million, four hundred thirty-one thousand, three hundred forty".