161786431 has 2 divisors, whose sum is σ = 161786432. Its totient is φ = 161786430.

The previous prime is 161786423. The next prime is 161786453. The reversal of 161786431 is 134687161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161786431 - 2³ = 161786423 is a prime.

It is a super-2 number, since 2×161786431² = 52349698511435522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161786491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80893215 + 80893216.

It is an arithmetic number, because the mean of its divisors is an integer number (80893216).

Almost surely, 2^161786431 is an apocalyptic number.

161786431 is a deficient number, since it is larger than the sum of its proper divisors (1).

161786431 is an equidigital number, since it uses as much as digits as its factorization.

161786431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 37.

The square root of 161786431 is about 12719.5295117390. The cubic root of 161786431 is about 544.8965165583.

The spelling of 161786431 in words is "one hundred sixty-one million, seven hundred eighty-six thousand, four hundred thirty-one".