161031911 has 2 divisors, whose sum is σ = 161031912. Its totient is φ = 161031910.

The previous prime is 161031851. The next prime is 161031953. The reversal of 161031911 is 119130161.

It is a strong prime.

It is an emirp because it is prime and its reverse (119130161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161031911 - 2¹⁰ = 161030887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161031961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80515955 + 80515956.

It is an arithmetic number, because the mean of its divisors is an integer number (80515956).

Almost surely, 2^161031911 is an apocalyptic number.

161031911 is a deficient number, since it is larger than the sum of its proper divisors (1).

161031911 is an equidigital number, since it uses as much as digits as its factorization.

161031911 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 23.

The square root of 161031911 is about 12689.8349477052. The cubic root of 161031911 is about 544.0481221397.

The spelling of 161031911 in words is "one hundred sixty-one million, thirty-one thousand, nine hundred eleven".