161993057 has 4 divisors (see below), whose sum is σ = 162036420. Its totient is φ = 161949696.

The previous prime is 161992969. The next prime is 161993063. The reversal of 161993057 is 750399161.

161993057 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 38427601 + 123565456 = 6199^2 + 11116^2 .

It is a cyclic number.

It is not a de Polignac number, because 161993057 - 2²⁶ = 94884193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161993087) 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, 15488 + ... + 23745.

It is an arithmetic number, because the mean of its divisors is an integer number (40509105).

Almost surely, 2^161993057 is an apocalyptic number.

It is an amenable number.

161993057 is a deficient number, since it is larger than the sum of its proper divisors (43363).

161993057 is an equidigital number, since it uses as much as digits as its factorization.

161993057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43362.

The product of its (nonzero) digits is 51030, while the sum is 41.

The square root of 161993057 is about 12727.6493116365. The cubic root of 161993057 is about 545.1283899185.

The spelling of 161993057 in words is "one hundred sixty-one million, nine hundred ninety-three thousand, fifty-seven".