161551259 has 4 divisors (see below), whose sum is σ = 162453960. Its totient is φ = 160648560.

The previous prime is 161551253. The next prime is 161551279. The reversal of 161551259 is 952155161.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161551259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161551253) 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 3 ways as a sum of consecutive naturals, for example, 451082 + ... + 451439.

It is an arithmetic number, because the mean of its divisors is an integer number (40613490).

Almost surely, 2^161551259 is an apocalyptic number.

161551259 is a deficient number, since it is larger than the sum of its proper divisors (902701).

161551259 is an equidigital number, since it uses as much as digits as its factorization.

161551259 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 902700.

The product of its digits is 13500, while the sum is 35.

The square root of 161551259 is about 12710.2816255188. The cubic root of 161551259 is about 544.6323688523.

The spelling of 161551259 in words is "one hundred sixty-one million, five hundred fifty-one thousand, two hundred fifty-nine".