161964817 has 4 divisors (see below), whose sum is σ = 185102656. Its totient is φ = 138826980.

The previous prime is 161964809. The next prime is 161964823. The reversal of 161964817 is 718469161.

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 161964817 - 2³ = 161964809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161964857) 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, 11568909 + ... + 11568922.

It is an arithmetic number, because the mean of its divisors is an integer number (46275664).

Almost surely, 2^161964817 is an apocalyptic number.

It is an amenable number.

161964817 is a deficient number, since it is larger than the sum of its proper divisors (23137839).

161964817 is an equidigital number, since it uses as much as digits as its factorization.

161964817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23137838.

The product of its digits is 72576, while the sum is 43.

The square root of 161964817 is about 12726.5398675367. The cubic root of 161964817 is about 545.0967109468.

The spelling of 161964817 in words is "one hundred sixty-one million, nine hundred sixty-four thousand, eight hundred seventeen".