161822257 has 8 divisors (see below), whose sum is σ = 165171200. Its totient is φ = 158515812.

The previous prime is 161822251. The next prime is 161822281. The reversal of 161822257 is 752228161.

It is a happy number.

It is not a de Polignac number, because 161822257 - 2³ = 161822249 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161822251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1274128 + ... + 1274254.

It is an arithmetic number, because the mean of its divisors is an integer number (20646400).

Almost surely, 2^161822257 is an apocalyptic number.

It is an amenable number.

161822257 is a deficient number, since it is larger than the sum of its proper divisors (3348943).

161822257 is an frugal number, since it uses more digits than its factorization.

161822257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 460 (or 206 counting only the distinct ones).

The product of its digits is 13440, while the sum is 34.

The square root of 161822257 is about 12720.9377405913. The cubic root of 161822257 is about 544.9367342323.

The spelling of 161822257 in words is "one hundred sixty-one million, eight hundred twenty-two thousand, two hundred fifty-seven".