21742456340664 has 96 divisors (see below), whose sum is σ = 60943609116000. Its totient is φ = 6994442547456.

The previous prime is 21742456340653. The next prime is 21742456340677. The reversal of 21742456340664 is 46604365424712.

21742456340664 is a `hidden beast` number, since 2 + 1 + 74 + 2 + 4 + 563 + 4 + 0 + 6 + 6 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21742456340664.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2343397 + ... + 6998315.

It is an arithmetic number, because the mean of its divisors is an integer number (634829261625).

Almost surely, 2^{21742456340664} is an apocalyptic number.

21742456340664 is a gapful number since it is divisible by the number (24) 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 21742456340664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30471804558000).

21742456340664 is an abundant number, since it is smaller than the sum of its proper divisors (39201152775336).

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

21742456340664 is a wasteful number, since it uses less digits than its factorization.

21742456340664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4657197 (or 4657190 counting only the distinct ones).

The product of its (nonzero) digits is 23224320, while the sum is 54.

The spelling of 21742456340664 in words is "twenty-one trillion, seven hundred forty-two billion, four hundred fifty-six million, three hundred forty thousand, six hundred sixty-four".