161975157 has 4 divisors (see below), whose sum is σ = 215966880. Its totient is φ = 107983436.

The previous prime is 161975153. The next prime is 161975161. The reversal of 161975157 is 751579161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 751579161 = 3 ⋅250526387.

It is an interprime number because it is at equal distance from previous prime (161975153) and next prime (161975161).

It is a cyclic number.

It is not a de Polignac number, because 161975157 - 2² = 161975153 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161975153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26995857 + ... + 26995862.

It is an arithmetic number, because the mean of its divisors is an integer number (53991720).

Almost surely, 2^161975157 is an apocalyptic number.

It is an amenable number.

161975157 is a deficient number, since it is larger than the sum of its proper divisors (53991723).

161975157 is an equidigital number, since it uses as much as digits as its factorization.

161975157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53991722.

The product of its digits is 66150, while the sum is 42.

The square root of 161975157 is about 12726.9460987308. The cubic root of 161975157 is about 545.1083105443.

The spelling of 161975157 in words is "one hundred sixty-one million, nine hundred seventy-five thousand, one hundred fifty-seven".