20423939 has 2 divisors, whose sum is σ = 20423940. Its totient is φ = 20423938.

The previous prime is 20423929. The next prime is 20423941. The reversal of 20423939 is 93932402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20423939 - 2¹² = 20419843 is a prime.

It is a Sophie Germain prime.

Together with 20423941, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20423929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10211969 + 10211970.

It is an arithmetic number, because the mean of its divisors is an integer number (10211970).

Almost surely, 2^20423939 is an apocalyptic number.

20423939 is a deficient number, since it is larger than the sum of its proper divisors (1).

20423939 is an equidigital number, since it uses as much as digits as its factorization.

20423939 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 32.

The square root of 20423939 is about 4519.2852310957. The cubic root of 20423939 is about 273.3462802050.

It can be divided in two parts, 2042393 and 9, that added together give a palindrome (2042402).

The spelling of 20423939 in words is "twenty million, four hundred twenty-three thousand, nine hundred thirty-nine".