161120731 has 2 divisors, whose sum is σ = 161120732. Its totient is φ = 161120730.

The previous prime is 161120717. The next prime is 161120761. The reversal of 161120731 is 137021161.

161120731 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161120731 - 2²³ = 152732123 is a prime.

It is a super-2 number, since 2×161120731² = 51919779915948722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161120761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80560365 + 80560366.

It is an arithmetic number, because the mean of its divisors is an integer number (80560366).

Almost surely, 2^161120731 is an apocalyptic number.

161120731 is a deficient number, since it is larger than the sum of its proper divisors (1).

161120731 is an equidigital number, since it uses as much as digits as its factorization.

161120731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 161120731 is about 12693.3341167717. The cubic root of 161120731 is about 544.1481302111.

Adding to 161120731 its reverse (137021161), we get a palindrome (298141892).

The spelling of 161120731 in words is "one hundred sixty-one million, one hundred twenty thousand, seven hundred thirty-one".