21715433 has 2 divisors, whose sum is σ = 21715434. Its totient is φ = 21715432.

The previous prime is 21715361. The next prime is 21715471. The reversal of 21715433 is 33451712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21270544 + 444889 = 4612^2 + 667^2 .

It is a cyclic number.

It is not a de Polignac number, because 21715433 - 2²² = 17521129 is a prime.

It is not a weakly prime, because it can be changed into another prime (21715333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10857716 + 10857717.

It is an arithmetic number, because the mean of its divisors is an integer number (10857717).

Almost surely, 2^21715433 is an apocalyptic number.

It is an amenable number.

21715433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21715433 is an equidigital number, since it uses as much as digits as its factorization.

21715433 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2520, while the sum is 26.

The square root of 21715433 is about 4659.9820815106. The cubic root of 21715433 is about 278.9905530732.

The spelling of 21715433 in words is "twenty-one million, seven hundred fifteen thousand, four hundred thirty-three".