161220258 has 12 divisors (see below), whose sum is σ = 349310598. Its totient is φ = 53740080.

The previous prime is 161220229. The next prime is 161220307. The reversal of 161220258 is 852022161.

It is a happy number.

161220258 is a `hidden beast` number, since 1 + 612 + 20 + 25 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 143352729 + 17867529 = 11973^2 + 4227^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4478323 + ... + 4478358.

Almost surely, 2^161220258 is an apocalyptic number.

161220258 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

161220258 is an abundant number, since it is smaller than the sum of its proper divisors (188090340).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161220258 is a wasteful number, since it uses less digits than its factorization.

161220258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8956689 (or 8956686 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 161220258 is about 12697.2539550881. The cubic root of 161220258 is about 544.2601503158.

The spelling of 161220258 in words is "one hundred sixty-one million, two hundred twenty thousand, two hundred fifty-eight".