21666343150564 has 48 divisors (see below), whose sum is σ = 43948033145856. Its totient is φ = 9153745524000.

The previous prime is 21666343150531. The next prime is 21666343150591. The reversal of 21666343150564 is 46505134366612.

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, 16881339 + ... + 18119389.

It is an arithmetic number, because the mean of its divisors is an integer number (915584023872).

Almost surely, 2^{21666343150564} is an apocalyptic number.

It is an amenable number.

21666343150564 is an abundant number, since it is smaller than the sum of its proper divisors (22281689995292).

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

21666343150564 is a wasteful number, since it uses less digits than its factorization.

21666343150564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1246936 (or 1246934 counting only the distinct ones).

The product of its (nonzero) digits is 9331200, while the sum is 52.

The spelling of 21666343150564 in words is "twenty-one trillion, six hundred sixty-six billion, three hundred forty-three million, one hundred fifty thousand, five hundred sixty-four".