21660157333782 has 144 divisors (see below), whose sum is σ = 53833132604160. Its totient is φ = 6277637609760.

The previous prime is 21660157333769. The next prime is 21660157333799. The reversal of 21660157333782 is 28733375106612.

21660157333782 is a `hidden beast` number, since 2 + 1 + 6 + 60 + 1 + 573 + 3 + 3 + 7 + 8 + 2 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 657567469 + ... + 657600407.

It is an arithmetic number, because the mean of its divisors is an integer number (373841198640).

Almost surely, 2^{21660157333782} is an apocalyptic number.

21660157333782 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21660157333782, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26916566302080).

21660157333782 is an abundant number, since it is smaller than the sum of its proper divisors (32172975270378).

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

21660157333782 is a wasteful number, since it uses less digits than its factorization.

21660157333782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46119 (or 46105 counting only the distinct ones).

The product of its (nonzero) digits is 7620480, while the sum is 54.

The spelling of 21660157333782 in words is "twenty-one trillion, six hundred sixty billion, one hundred fifty-seven million, three hundred thirty-three thousand, seven hundred eighty-two".