20816623 has 2 divisors, whose sum is σ = 20816624. Its totient is φ = 20816622.

The previous prime is 20816617. The next prime is 20816659. The reversal of 20816623 is 32661802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20816623 - 2⁹ = 20816111 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20816591 and 20816600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20816603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10408311 + 10408312.

It is an arithmetic number, because the mean of its divisors is an integer number (10408312).

Almost surely, 2^20816623 is an apocalyptic number.

20816623 is a deficient number, since it is larger than the sum of its proper divisors (1).

20816623 is an equidigital number, since it uses as much as digits as its factorization.

20816623 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 20816623 is about 4562.5237533628. The cubic root of 20816623 is about 275.0870159895.

The spelling of 20816623 in words is "twenty million, eight hundred sixteen thousand, six hundred twenty-three".