21445799 has 2 divisors, whose sum is σ = 21445800. Its totient is φ = 21445798.

The previous prime is 21445793. The next prime is 21445807. The reversal of 21445799 is 99754412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21445799 - 2¹² = 21441703 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21445793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10722899 + 10722900.

It is an arithmetic number, because the mean of its divisors is an integer number (10722900).

Almost surely, 2^21445799 is an apocalyptic number.

21445799 is a deficient number, since it is larger than the sum of its proper divisors (1).

21445799 is an equidigital number, since it uses as much as digits as its factorization.

21445799 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 41.

The square root of 21445799 is about 4630.9609154041. The cubic root of 21445799 is about 277.8310266569.

The spelling of 21445799 in words is "twenty-one million, four hundred forty-five thousand, seven hundred ninety-nine".