16661166722025 has 96 divisors (see below), whose sum is σ = 31601596535040. Its totient is φ = 7587530219520.

The previous prime is 16661166721987. The next prime is 16661166722051. The reversal of 16661166722025 is 52022766116661.

It is not a de Polignac number, because 16661166722025 - 2⁸ = 16661166721769 is a prime.

It is a super-2 number, since 2×16661166722025² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1094897217 + ... + 1094912433.

It is an arithmetic number, because the mean of its divisors is an integer number (329183297240).

Almost surely, 2^{16661166722025} is an apocalyptic number.

16661166722025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16661166722025 is a deficient number, since it is larger than the sum of its proper divisors (14940429813015).

16661166722025 is a wasteful number, since it uses less digits than its factorization.

16661166722025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23043 (or 23038 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 51.

The spelling of 16661166722025 in words is "sixteen trillion, six hundred sixty-one billion, one hundred sixty-six million, seven hundred twenty-two thousand, twenty-five".