161590901 has 2 divisors, whose sum is σ = 161590902. Its totient is φ = 161590900.

The previous prime is 161590883. The next prime is 161590903. The reversal of 161590901 is 109095161.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 158734801 + 2856100 = 12599^2 + 1690^2 .

It is a cyclic number.

It is not a de Polignac number, because 161590901 - 2¹⁰ = 161589877 is a prime.

It is a super-2 number, since 2×161590901² = 52223238571983602, which contains 22 as substring.

Together with 161590903, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161590903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80795450 + 80795451.

It is an arithmetic number, because the mean of its divisors is an integer number (80795451).

Almost surely, 2^161590901 is an apocalyptic number.

It is an amenable number.

161590901 is a deficient number, since it is larger than the sum of its proper divisors (1).

161590901 is an equidigital number, since it uses as much as digits as its factorization.

161590901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2430, while the sum is 32.

The square root of 161590901 is about 12711.8409760349. The cubic root of 161590901 is about 544.6769131263.

The spelling of 161590901 in words is "one hundred sixty-one million, five hundred ninety thousand, nine hundred one".