161913431 has 2 divisors, whose sum is σ = 161913432. Its totient is φ = 161913430.

The previous prime is 161913419. The next prime is 161913439. The reversal of 161913431 is 134319161.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161913431 is a prime.

It is a super-2 number, since 2×161913431² = 52431918276383522, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 161913394 and 161913403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161913439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80956715 + 80956716.

It is an arithmetic number, because the mean of its divisors is an integer number (80956716).

Almost surely, 2^161913431 is an apocalyptic number.

161913431 is a deficient number, since it is larger than the sum of its proper divisors (1).

161913431 is an equidigital number, since it uses as much as digits as its factorization.

161913431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 29.

The square root of 161913431 is about 12724.5208554193. The cubic root of 161913431 is about 545.0390578859.

The spelling of 161913431 in words is "one hundred sixty-one million, nine hundred thirteen thousand, four hundred thirty-one".