161326251 has 6 divisors (see below), whose sum is σ = 233026820. Its totient is φ = 107550828.

The previous prime is 161326241. The next prime is 161326279. The reversal of 161326251 is 152623161.

161326251 is a `hidden beast` number, since 1 + 6 + 1 + 32 + 625 + 1 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-161326251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161326241) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8962561 + ... + 8962578.

Almost surely, 2^161326251 is an apocalyptic number.

161326251 is a deficient number, since it is larger than the sum of its proper divisors (71700569).

161326251 is a wasteful number, since it uses less digits than its factorization.

161326251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17925145 (or 17925142 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 161326251 is about 12701.4271245400. The cubic root of 161326251 is about 544.3793973826.

The spelling of 161326251 in words is "one hundred sixty-one million, three hundred twenty-six thousand, two hundred fifty-one".