161868631 has 2 divisors, whose sum is σ = 161868632. Its totient is φ = 161868630.

The previous prime is 161868601. The next prime is 161868647. The reversal of 161868631 is 136868161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161868631 - 2¹¹ = 161866583 is a prime.

It is a super-2 number, since 2×161868631² = 52402907403628322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161868601) by changing a digit.

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 as a sum of consecutive naturals, namely, 80934315 + 80934316.

It is an arithmetic number, because the mean of its divisors is an integer number (80934316).

Almost surely, 2^161868631 is an apocalyptic number.

161868631 is a deficient number, since it is larger than the sum of its proper divisors (1).

161868631 is an equidigital number, since it uses as much as digits as its factorization.

161868631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 40.

The square root of 161868631 is about 12722.7603530052. The cubic root of 161868631 is about 544.9887841027.

The spelling of 161868631 in words is "one hundred sixty-one million, eight hundred sixty-eight thousand, six hundred thirty-one".