161304251 has 4 divisors (see below), whose sum is σ = 161932152. Its totient is φ = 160676352.

The previous prime is 161304233. The next prime is 161304259. The reversal of 161304251 is 152403161.

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

It is a cyclic number.

It is not a de Polignac number, because 161304251 - 2¹⁸ = 161042107 is a prime.

It is a super-2 number, since 2×161304251² = 52038122781342002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161304259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 313565 + ... + 314078.

It is an arithmetic number, because the mean of its divisors is an integer number (40483038).

Almost surely, 2^161304251 is an apocalyptic number.

161304251 is a deficient number, since it is larger than the sum of its proper divisors (627901).

161304251 is an equidigital number, since it uses as much as digits as its factorization.

161304251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627900.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 161304251 is about 12700.5610505993. The cubic root of 161304251 is about 544.3546506533.

The spelling of 161304251 in words is "one hundred sixty-one million, three hundred four thousand, two hundred fifty-one".