161245531 has 2 divisors, whose sum is σ = 161245532. Its totient is φ = 161245530.

The previous prime is 161245499. The next prime is 161245547. The reversal of 161245531 is 135542161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161245531 - 2⁵ = 161245499 is a prime.

It is a super-2 number, since 2×161245531² = 52000242534943922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161245531.

It is not a weakly prime, because it can be changed into another prime (161225531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80622765 + 80622766.

It is an arithmetic number, because the mean of its divisors is an integer number (80622766).

Almost surely, 2^161245531 is an apocalyptic number.

161245531 is a deficient number, since it is larger than the sum of its proper divisors (1).

161245531 is an equidigital number, since it uses as much as digits as its factorization.

161245531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3600, while the sum is 28.

The square root of 161245531 is about 12698.2491312779. The cubic root of 161245531 is about 544.2885883634.

Adding to 161245531 its reverse (135542161), we get a palindrome (296787692).

The spelling of 161245531 in words is "one hundred sixty-one million, two hundred forty-five thousand, five hundred thirty-one".