21731357042340 has 384 divisors, whose sum is σ = 67460146790400. Its totient is φ = 5183264808960.

The previous prime is 21731357042323. The next prime is 21731357042383. The reversal of 21731357042340 is 4324075313712.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21731357042292 and 21731357042301.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 6469589581 + ... + 6469592939.

It is an arithmetic number, because the mean of its divisors is an integer number (175677465600).

Almost surely, 2^{21731357042340} is an apocalyptic number.

21731357042340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21731357042340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33730073395200).

21731357042340 is an abundant number, since it is smaller than the sum of its proper divisors (45728789748060).

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

21731357042340 is a wasteful number, since it uses less digits than its factorization.

21731357042340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4107 (or 4105 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 42.

The spelling of 21731357042340 in words is "twenty-one trillion, seven hundred thirty-one billion, three hundred fifty-seven million, forty-two thousand, three hundred forty".