161502545561 has 16 divisors (see below), whose sum is σ = 192723148800. Its totient is φ = 132326885328.

The previous prime is 161502545543. The next prime is 161502545629. The reversal of 161502545561 is 165545205161.

It is a cyclic number.

It is not a de Polignac number, because 161502545561 - 2³⁰ = 160428803737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161502541561) 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, 70721 + ... + 572718.

It is an arithmetic number, because the mean of its divisors is an integer number (12045196800).

Almost surely, 2^161502545561 is an apocalyptic number.

It is an amenable number.

161502545561 is a deficient number, since it is larger than the sum of its proper divisors (31220603239).

161502545561 is a wasteful number, since it uses less digits than its factorization.

161502545561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645028.

The product of its (nonzero) digits is 180000, while the sum is 41.

The spelling of 161502545561 in words is "one hundred sixty-one billion, five hundred two million, five hundred forty-five thousand, five hundred sixty-one".