161537435539865 has 64 divisors (see below), whose sum is σ = 253196288114688. Its totient is φ = 95995834387200.

The previous prime is 161537435539861. The next prime is 161537435539889. The reversal of 161537435539865 is 568935534735161.

It is not a de Polignac number, because 161537435539865 - 2² = 161537435539861 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161537435539861) 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, 100206074 + ... + 101805363.

It is an arithmetic number, because the mean of its divisors is an integer number (3956192001792).

Almost surely, 2^{161537435539865} is an apocalyptic number.

It is an amenable number.

161537435539865 is a deficient number, since it is larger than the sum of its proper divisors (91658852574823).

161537435539865 is a wasteful number, since it uses less digits than its factorization.

161537435539865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202011558.

The product of its digits is 1224720000, while the sum is 71.

The spelling of 161537435539865 in words is "one hundred sixty-one trillion, five hundred thirty-seven billion, four hundred thirty-five million, five hundred thirty-nine thousand, eight hundred sixty-five".