161868626645 has 30 divisors (see below), whose sum is σ = 213809045910. Its totient is φ = 117643469680.

The previous prime is 161868626641. The next prime is 161868626653. The reversal of 161868626645 is 546626868161.

It can be written as a sum of positive squares in only one way, i.e., 129494901316 + 32373725329 = 359854^2 + 179927^2 .

It is not a de Polignac number, because 161868626645 - 2² = 161868626641 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161868626641) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 108855092 + ... + 108856578.

It is an arithmetic number, because the mean of its divisors is an integer number (7126968197).

Almost surely, 2^161868626645 is an apocalyptic number.

It is an amenable number.

161868626645 is a deficient number, since it is larger than the sum of its proper divisors (51940419265).

161868626645 is an frugal number, since it uses more digits than its factorization.

161868626645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3023 (or 1503 counting only the distinct ones).

The product of its digits is 19906560, while the sum is 59.

The spelling of 161868626645 in words is "one hundred sixty-one billion, eight hundred sixty-eight million, six hundred twenty-six thousand, six hundred forty-five".