20664747727542 has 64 divisors (see below), whose sum is σ = 46382788408320. Its totient is φ = 6819124320000.

The previous prime is 20664747727501. The next prime is 20664747727583. The reversal of 20664747727542 is 24572774746602.

20664747727542 is a `hidden beast` number, since 2 + 0 + 6 + 6 + 47 + 47 + 7 + 2 + 7 + 542 = 666.

It is an interprime number because it is at equal distance from previous prime (20664747727501) and next prime (20664747727583).

It is a self number, because there is not a number n which added to its sum of digits gives 20664747727542.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16303167 + ... + 17524917.

It is an arithmetic number, because the mean of its divisors is an integer number (724731068880).

Almost surely, 2^{20664747727542} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20664747727542, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23191394204160).

20664747727542 is an abundant number, since it is smaller than the sum of its proper divisors (25718040680778).

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

20664747727542 is a wasteful number, since it uses less digits than its factorization.

20664747727542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1224906 (or 1224900 counting only the distinct ones).

The product of its (nonzero) digits is 221276160, while the sum is 63.

The spelling of 20664747727542 in words is "twenty trillion, six hundred sixty-four billion, seven hundred forty-seven million, seven hundred twenty-seven thousand, five hundred forty-two".