161731357 has 2 divisors, whose sum is σ = 161731358. Its totient is φ = 161731356.

The previous prime is 161731327. The next prime is 161731373. The reversal of 161731357 is 753137161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 152127556 + 9603801 = 12334^2 + 3099^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161731357 is a prime.

It is a super-2 number, since 2×161731357² = 52314063674122898, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161731307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80865678 + 80865679.

It is an arithmetic number, because the mean of its divisors is an integer number (80865679).

Almost surely, 2^161731357 is an apocalyptic number.

It is an amenable number.

161731357 is a deficient number, since it is larger than the sum of its proper divisors (1).

161731357 is an equidigital number, since it uses as much as digits as its factorization.

161731357 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13230, while the sum is 34.

The square root of 161731357 is about 12717.3643888976. The cubic root of 161731357 is about 544.8346798179.

The spelling of 161731357 in words is "one hundred sixty-one million, seven hundred thirty-one thousand, three hundred fifty-seven".