161091983585 has 16 divisors (see below), whose sum is σ = 209237179536. Its totient is φ = 118356365568.

The previous prime is 161091983551. The next prime is 161091983609. The reversal of 161091983585 is 585389190161.

It can be written as a sum of positive squares in 8 ways, for example, as 14311815424 + 146780168161 = 119632^2 + 383119^2 .

It is a cyclic number.

It is not a de Polignac number, because 161091983585 - 2¹⁰ = 161091982561 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 161091983585.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6277394 + ... + 6303003.

It is an arithmetic number, because the mean of its divisors is an integer number (13077323721).

Almost surely, 2^161091983585 is an apocalyptic number.

It is an amenable number.

161091983585 is a deficient number, since it is larger than the sum of its proper divisors (48145195951).

161091983585 is a wasteful number, since it uses less digits than its factorization.

161091983585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12580612.

The product of its (nonzero) digits is 2332800, while the sum is 56.

The spelling of 161091983585 in words is "one hundred sixty-one billion, ninety-one million, nine hundred eighty-three thousand, five hundred eighty-five".