161393731 has 2 divisors, whose sum is σ = 161393732. Its totient is φ = 161393730.

The previous prime is 161393711. The next prime is 161393747. The reversal of 161393731 is 137393161.

161393731 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 a cyclic number.

It is not a de Polignac number, because 161393731 - 2¹⁵ = 161360963 is a prime.

It is a super-2 number, since 2×161393731² = 52095872812200722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161393711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80696865 + 80696866.

It is an arithmetic number, because the mean of its divisors is an integer number (80696866).

Almost surely, 2^161393731 is an apocalyptic number.

161393731 is a deficient number, since it is larger than the sum of its proper divisors (1).

161393731 is an equidigital number, since it uses as much as digits as its factorization.

161393731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10206, while the sum is 34.

The square root of 161393731 is about 12704.0832412260. The cubic root of 161393731 is about 544.4552883197.

The spelling of 161393731 in words is "one hundred sixty-one million, three hundred ninety-three thousand, seven hundred thirty-one".