21445759 has 2 divisors, whose sum is σ = 21445760. Its totient is φ = 21445758.

The previous prime is 21445757. The next prime is 21445793. The reversal of 21445759 is 95754412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21445759 - 2¹ = 21445757 is a prime.

Together with 21445757, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21445751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10722879 + 10722880.

It is an arithmetic number, because the mean of its divisors is an integer number (10722880).

Almost surely, 2^21445759 is an apocalyptic number.

21445759 is a deficient number, since it is larger than the sum of its proper divisors (1).

21445759 is an equidigital number, since it uses as much as digits as its factorization.

21445759 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 37.

The square root of 21445759 is about 4630.9565966439. The cubic root of 21445759 is about 277.8308539231.

The spelling of 21445759 in words is "twenty-one million, four hundred forty-five thousand, seven hundred fifty-nine".