21183994723 has 2 divisors, whose sum is σ = 21183994724. Its totient is φ = 21183994722.

The previous prime is 21183994709. The next prime is 21183994751. The reversal of 21183994723 is 32749938112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21183994723 - 2²¹ = 21181897571 is a prime.

It is not a weakly prime, because it can be changed into another prime (21183998723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10591997361 + 10591997362.

It is an arithmetic number, because the mean of its divisors is an integer number (10591997362).

Almost surely, 2^21183994723 is an apocalyptic number.

21183994723 is a deficient number, since it is larger than the sum of its proper divisors (1).

21183994723 is an equidigital number, since it uses as much as digits as its factorization.

21183994723 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 49.

The spelling of 21183994723 in words is "twenty-one billion, one hundred eighty-three million, nine hundred ninety-four thousand, seven hundred twenty-three".