161971177 has 4 divisors (see below), whose sum is σ = 167556420. Its totient is φ = 156385936.

The previous prime is 161971141. The next prime is 161971213. The reversal of 161971177 is 771179161.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (161971141) and next prime (161971213).

It can be written as a sum of positive squares in 2 ways, for example, as 137804121 + 24167056 = 11739^2 + 4916^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161971177 is a prime.

It is a super-3 number, since 3×161971177³ (a number of 26 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161971477) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2792578 + ... + 2792635.

It is an arithmetic number, because the mean of its divisors is an integer number (41889105).

Almost surely, 2^161971177 is an apocalyptic number.

It is an amenable number.

161971177 is a deficient number, since it is larger than the sum of its proper divisors (5585243).

161971177 is an equidigital number, since it uses as much as digits as its factorization.

161971177 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5585242.

The product of its digits is 18522, while the sum is 40.

The square root of 161971177 is about 12726.7897366147. The cubic root of 161971177 is about 545.1038457673.

The spelling of 161971177 in words is "one hundred sixty-one million, nine hundred seventy-one thousand, one hundred seventy-seven".