21183923 has 2 divisors, whose sum is σ = 21183924. Its totient is φ = 21183922.

The previous prime is 21183919. The next prime is 21183931. The reversal of 21183923 is 32938112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21183923 - 2² = 21183919 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21183913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10591961 + 10591962.

It is an arithmetic number, because the mean of its divisors is an integer number (10591962).

Almost surely, 2^21183923 is an apocalyptic number.

21183923 is a deficient number, since it is larger than the sum of its proper divisors (1).

21183923 is an equidigital number, since it uses as much as digits as its factorization.

21183923 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 29.

The square root of 21183923 is about 4602.5995915352. The cubic root of 21183923 is about 276.6955214175.

The spelling of 21183923 in words is "twenty-one million, one hundred eighty-three thousand, nine hundred twenty-three".