21923689 has 2 divisors, whose sum is σ = 21923690. Its totient is φ = 21923688.

The previous prime is 21923683. The next prime is 21923717. The reversal of 21923689 is 98632912.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21086464 + 837225 = 4592^2 + 915^2 .

It is a cyclic number.

It is not a de Polignac number, because 21923689 - 2¹³ = 21915497 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21923683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10961844 + 10961845.

It is an arithmetic number, because the mean of its divisors is an integer number (10961845).

Almost surely, 2^21923689 is an apocalyptic number.

It is an amenable number.

21923689 is a deficient number, since it is larger than the sum of its proper divisors (1).

21923689 is an equidigital number, since it uses as much as digits as its factorization.

21923689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 40.

The square root of 21923689 is about 4682.2739133887. The cubic root of 21923689 is about 279.8795783188.

The spelling of 21923689 in words is "twenty-one million, nine hundred twenty-three thousand, six hundred eighty-nine".