21631004378940 has 48 divisors (see below), whose sum is σ = 66072886104960. Its totient is φ = 5243879849280.

The previous prime is 21631004378923. The next prime is 21631004378983. The reversal of 21631004378940 is 4987340013612.

It is a self number, because there is not a number n which added to its sum of digits gives 21631004378940.

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, 16387123870 + ... + 16387125189.

It is an arithmetic number, because the mean of its divisors is an integer number (1376518460520).

Almost surely, 2^{21631004378940} is an apocalyptic number.

21631004378940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21631004378940 is an abundant number, since it is smaller than the sum of its proper divisors (44441881726020).

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

21631004378940 is a wasteful number, since it uses less digits than its factorization.

21631004378940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32774249082 (or 32774249080 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 48.

The spelling of 21631004378940 in words is "twenty-one trillion, six hundred thirty-one billion, four million, three hundred seventy-eight thousand, nine hundred forty".