16561723 has 8 divisors (see below), whose sum is σ = 17601840. Its totient is φ = 15582880.

The previous prime is 16561717. The next prime is 16561763. The reversal of 16561723 is 32716561.

It is not a de Polignac number, because 16561723 - 2⁵ = 16561691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16561703) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3228 + ... + 6598.

It is an arithmetic number, because the mean of its divisors is an integer number (2200230).

Almost surely, 2^16561723 is an apocalyptic number.

16561723 is a deficient number, since it is larger than the sum of its proper divisors (1040117).

16561723 is an frugal number, since it uses more digits than its factorization.

16561723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3422 (or 3388 counting only the distinct ones).

The product of its digits is 7560, while the sum is 31.

The square root of 16561723 is about 4069.6096864441. The cubic root of 16561723 is about 254.8992194342.

The spelling of 16561723 in words is "sixteen million, five hundred sixty-one thousand, seven hundred twenty-three".