161390258 has 4 divisors (see below), whose sum is σ = 242085390. Its totient is φ = 80695128.

The previous prime is 161390221. The next prime is 161390261. The reversal of 161390258 is 852093161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 160706329 + 683929 = 12677^2 + 827^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40347563 + ... + 40347566.

Almost surely, 2^161390258 is an apocalyptic number.

161390258 is a deficient number, since it is larger than the sum of its proper divisors (80695132).

161390258 is an equidigital number, since it uses as much as digits as its factorization.

161390258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80695131.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 161390258 is about 12703.9465521546. The cubic root of 161390258 is about 544.4513829495.

The spelling of 161390258 in words is "one hundred sixty-one million, three hundred ninety thousand, two hundred fifty-eight".