20716723 has 4 divisors (see below), whose sum is σ = 20979040. Its totient is φ = 20454408.

The previous prime is 20716697. The next prime is 20716739. The reversal of 20716723 is 32761702.

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 20716723 - 2¹⁷ = 20585651 is a prime.

It is a super-2 number, since 2×20716723² = 858365223717458, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20716691 and 20716700.

It is not an unprimeable number, because it can be changed into a prime (20716753) 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, 131040 + ... + 131197.

It is an arithmetic number, because the mean of its divisors is an integer number (5244760).

Almost surely, 2^20716723 is an apocalyptic number.

20716723 is a deficient number, since it is larger than the sum of its proper divisors (262317).

20716723 is an equidigital number, since it uses as much as digits as its factorization.

20716723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262316.

The product of its (nonzero) digits is 3528, while the sum is 28.

The square root of 20716723 is about 4551.5626986783. The cubic root of 20716723 is about 274.6462581125.

The spelling of 20716723 in words is "twenty million, seven hundred sixteen thousand, seven hundred twenty-three".