20161723 has 4 divisors (see below), whose sum is σ = 20248488. Its totient is φ = 20074960.

The previous prime is 20161697. The next prime is 20161727. The reversal of 20161723 is 32716102.

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 20161723 - 2¹³ = 20153531 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20161694 and 20161703.

It is not an unprimeable number, because it can be changed into a prime (20161727) 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, 43033 + ... + 43498.

It is an arithmetic number, because the mean of its divisors is an integer number (5062122).

Almost surely, 2^20161723 is an apocalyptic number.

20161723 is a deficient number, since it is larger than the sum of its proper divisors (86765).

20161723 is an equidigital number, since it uses as much as digits as its factorization.

20161723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86764.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 20161723 is about 4490.1807313292. The cubic root of 20161723 is about 272.1714380222.

Adding to 20161723 its reverse (32716102), we get a palindrome (52877825).

The spelling of 20161723 in words is "twenty million, one hundred sixty-one thousand, seven hundred twenty-three".