20309923 has 2 divisors, whose sum is σ = 20309924. Its totient is φ = 20309922.

The previous prime is 20309921. The next prime is 20309941. The reversal of 20309923 is 32990302.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20309923 - 2¹ = 20309921 is a prime.

Together with 20309921, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 20309891 and 20309900.

It is not a weakly prime, because it can be changed into another prime (20309921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10154961 + 10154962.

It is an arithmetic number, because the mean of its divisors is an integer number (10154962).

Almost surely, 2^20309923 is an apocalyptic number.

20309923 is a deficient number, since it is larger than the sum of its proper divisors (1).

20309923 is an equidigital number, since it uses as much as digits as its factorization.

20309923 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2916, while the sum is 28.

The square root of 20309923 is about 4506.6531927806. The cubic root of 20309923 is about 272.8366817359.

The spelling of 20309923 in words is "twenty million, three hundred nine thousand, nine hundred twenty-three".