161975213 has 4 divisors (see below), whose sum is σ = 162059040. Its totient is φ = 161891388.

The previous prime is 161975197. The next prime is 161975221. The reversal of 161975213 is 312579161.

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.

It is a cyclic number.

It is not a de Polignac number, because 161975213 - 2⁴ = 161975197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161975263) 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, 38945 + ... + 42902.

It is an arithmetic number, because the mean of its divisors is an integer number (40514760).

Almost surely, 2^161975213 is an apocalyptic number.

It is an amenable number.

161975213 is a deficient number, since it is larger than the sum of its proper divisors (83827).

161975213 is an equidigital number, since it uses as much as digits as its factorization.

161975213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83826.

The product of its digits is 11340, while the sum is 35.

The square root of 161975213 is about 12726.9482987871. The cubic root of 161975213 is about 545.1083733648.

The spelling of 161975213 in words is "one hundred sixty-one million, nine hundred seventy-five thousand, two hundred thirteen".