16521660066772 has 24 divisors (see below), whose sum is σ = 33936382841984. Its totient is φ = 6889340876832.

The previous prime is 16521660066767. The next prime is 16521660066797. The reversal of 16521660066772 is 27766006612561.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7973773128 + ... + 7973775199.

Almost surely, 2^{16521660066772} is an apocalyptic number.

It is an amenable number.

16521660066772 is an abundant number, since it is smaller than the sum of its proper divisors (17414722775212).

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

16521660066772 is a wasteful number, since it uses less digits than its factorization.

16521660066772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15947548375 (or 15947548373 counting only the distinct ones).

The product of its (nonzero) digits is 7620480, while the sum is 55.

The spelling of 16521660066772 in words is "sixteen trillion, five hundred twenty-one billion, six hundred sixty million, sixty-six thousand, seven hundred seventy-two".