165561151101591 has 16 divisors (see below), whose sum is σ = 252785216807424. Its totient is φ = 94418287813344.

The previous prime is 165561151101589. The next prime is 165561151101659. The reversal of 165561151101591 is 195101151165561.

It is not a de Polignac number, because 165561151101591 - 2¹ = 165561151101589 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165561151101591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165561151101581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7836832716 + ... + 7836853841.

It is an arithmetic number, because the mean of its divisors is an integer number (15799076050464).

Almost surely, 2^{165561151101591} is an apocalyptic number.

165561151101591 is a deficient number, since it is larger than the sum of its proper divisors (87224065705833).

165561151101591 is a wasteful number, since it uses less digits than its factorization.

165561151101591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15673687070.

The product of its (nonzero) digits is 202500, while the sum is 48.

The spelling of 165561151101591 in words is "one hundred sixty-five trillion, five hundred sixty-one billion, one hundred fifty-one million, one hundred one thousand, five hundred ninety-one".