161931963 has 4 divisors (see below), whose sum is σ = 215909288. Its totient is φ = 107954640.

The previous prime is 161931961. The next prime is 161931989. The reversal of 161931963 is 369139161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 369139161 = 3 ⋅123046387.

It is not a de Polignac number, because 161931963 - 2¹ = 161931961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161931961) 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, 26988658 + ... + 26988663.

It is an arithmetic number, because the mean of its divisors is an integer number (53977322).

Almost surely, 2^161931963 is an apocalyptic number.

161931963 is a deficient number, since it is larger than the sum of its proper divisors (53977325).

161931963 is an equidigital number, since it uses as much as digits as its factorization.

161931963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53977324.

The product of its digits is 26244, while the sum is 39.

The square root of 161931963 is about 12725.2490348912. The cubic root of 161931963 is about 545.0598514636.

The spelling of 161931963 in words is "one hundred sixty-one million, nine hundred thirty-one thousand, nine hundred sixty-three".