16661975 has 12 divisors (see below), whose sum is σ = 22539480. Its totient is φ = 12117600.

The previous prime is 16661971. The next prime is 16661987. The reversal of 16661975 is 57916661.

It is not a de Polignac number, because 16661975 - 2² = 16661971 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661971) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30020 + ... + 30569.

It is an arithmetic number, because the mean of its divisors is an integer number (1878290).

Almost surely, 2^16661975 is an apocalyptic number.

16661975 is a deficient number, since it is larger than the sum of its proper divisors (5877505).

16661975 is a wasteful number, since it uses less digits than its factorization.

16661975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60610 (or 60605 counting only the distinct ones).

The product of its digits is 68040, while the sum is 41.

The square root of 16661975 is about 4081.9082547260. The cubic root of 16661975 is about 255.4125067590.

The spelling of 16661975 in words is "sixteen million, six hundred sixty-one thousand, nine hundred seventy-five".