16661572150721 has 16 divisors (see below), whose sum is σ = 16954458892800. Its totient is φ = 16369328923200.

The previous prime is 16661572150711. The next prime is 16661572150733. The reversal of 16661572150721 is 12705127516661.

It is a cyclic number.

It is not a de Polignac number, because 16661572150721 - 2²² = 16661567956417 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16661572150721.

It is not an unprimeable number, because it can be changed into a prime (16661572150711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 347229551 + ... + 347277531.

It is an arithmetic number, because the mean of its divisors is an integer number (1059653680800).

Almost surely, 2^{16661572150721} is an apocalyptic number.

It is an amenable number.

16661572150721 is a deficient number, since it is larger than the sum of its proper divisors (292886742079).

16661572150721 is a wasteful number, since it uses less digits than its factorization.

16661572150721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54560.

The product of its (nonzero) digits is 1058400, while the sum is 50.

The spelling of 16661572150721 in words is "sixteen trillion, six hundred sixty-one billion, five hundred seventy-two million, one hundred fifty thousand, seven hundred twenty-one".