161671607565 has 16 divisors (see below), whose sum is σ = 278572616448. Its totient is φ = 79592175936.

The previous prime is 161671607543. The next prime is 161671607597. The reversal of 161671607565 is 565706176161.

It is not a de Polignac number, because 161671607565 - 2⁵ = 161671607533 is a prime.

It is a super-2 number, since 2×161671607565² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 414542389 + ... + 414542778.

It is an arithmetic number, because the mean of its divisors is an integer number (17410788528).

Almost surely, 2^161671607565 is an apocalyptic number.

161671607565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161671607565 is a deficient number, since it is larger than the sum of its proper divisors (116901008883).

161671607565 is a wasteful number, since it uses less digits than its factorization.

161671607565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 829085188.

The product of its (nonzero) digits is 1587600, while the sum is 51.

The spelling of 161671607565 in words is "one hundred sixty-one billion, six hundred seventy-one million, six hundred seven thousand, five hundred sixty-five".