161769931 has 2 divisors, whose sum is σ = 161769932. Its totient is φ = 161769930.

The previous prime is 161769901. The next prime is 161769941. The reversal of 161769931 is 139967161.

161769931 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (139967161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161769931 - 2¹⁷ = 161638859 is a prime.

It is a super-2 number, since 2×161769931² = 52339021151489522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161769901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80884965 + 80884966.

It is an arithmetic number, because the mean of its divisors is an integer number (80884966).

Almost surely, 2^161769931 is an apocalyptic number.

161769931 is a deficient number, since it is larger than the sum of its proper divisors (1).

161769931 is an equidigital number, since it uses as much as digits as its factorization.

161769931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61236, while the sum is 43.

The square root of 161769931 is about 12718.8808863044. The cubic root of 161769931 is about 544.8779919348.

The spelling of 161769931 in words is "one hundred sixty-one million, seven hundred sixty-nine thousand, nine hundred thirty-one".