16661657223145 has 64 divisors (see below), whose sum is σ = 22721261363712. Its totient is φ = 11621643264000.

The previous prime is 16661657223061. The next prime is 16661657223149. The reversal of 16661657223145 is 54132275616661.

It is a de Polignac number, because none of the positive numbers 2^k-16661657223145 is a prime.

It is a super-2 number, since 2×16661657223145² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16661657223149) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1010953305 + ... + 1010969785.

It is an arithmetic number, because the mean of its divisors is an integer number (355019708808).

Almost surely, 2^{16661657223145} is an apocalyptic number.

It is an amenable number.

16661657223145 is a deficient number, since it is larger than the sum of its proper divisors (6059604140567).

16661657223145 is a wasteful number, since it uses less digits than its factorization.

16661657223145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23602.

The product of its digits is 10886400, while the sum is 55.

The spelling of 16661657223145 in words is "sixteen trillion, six hundred sixty-one billion, six hundred fifty-seven million, two hundred twenty-three thousand, one hundred forty-five".