161603723 has 4 divisors (see below), whose sum is σ = 161705160. Its totient is φ = 161502288.

The previous prime is 161603707. The next prime is 161603749. The reversal of 161603723 is 327306161.

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

It is a cyclic number.

It is not a de Polignac number, because 161603723 - 2⁴ = 161603707 is a prime.

It is a super-2 number, since 2×161603723² = 52231526574921458, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161603023) 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, 48290 + ... + 51527.

It is an arithmetic number, because the mean of its divisors is an integer number (40426290).

Almost surely, 2^161603723 is an apocalyptic number.

161603723 is a deficient number, since it is larger than the sum of its proper divisors (101437).

161603723 is an equidigital number, since it uses as much as digits as its factorization.

161603723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101436.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 161603723 is about 12712.3452989604. The cubic root of 161603723 is about 544.6913191822.

Adding to 161603723 its reverse (327306161), we get a palindrome (488909884).

The spelling of 161603723 in words is "one hundred sixty-one million, six hundred three thousand, seven hundred twenty-three".