165161561516501 has 6 divisors (see below), whose sum is σ = 181541220510006. Its totient is φ = 150146874105800.

The previous prime is 165161561516459. The next prime is 165161561516527. The reversal of 165161561516501 is 105615165161561.

165161561516501 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 158070924535876 + 7090636980625 = 12572626^2 + 2662825^2 .

It is a de Polignac number, because none of the positive numbers 2^k-165161561516501 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 165161561516501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165161561566501) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 682485791270 + ... + 682485791511.

It is an arithmetic number, because the mean of its divisors is an integer number (30256870085001).

Almost surely, 2^{165161561516501} is an apocalyptic number.

165161561516501 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165161561516501 is a deficient number, since it is larger than the sum of its proper divisors (16379658993505).

165161561516501 is a wasteful number, since it uses less digits than its factorization.

165161561516501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1364971582803 (or 1364971582792 counting only the distinct ones).

The product of its (nonzero) digits is 810000, while the sum is 50.

The spelling of 165161561516501 in words is "one hundred sixty-five trillion, one hundred sixty-one billion, five hundred sixty-one million, five hundred sixteen thousand, five hundred one".