21952817 has 4 divisors (see below), whose sum is σ = 22011120. Its totient is φ = 21894516.

The previous prime is 21952811. The next prime is 21952823. The reversal of 21952817 is 71825912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (21952811) and next prime (21952823).

It is a cyclic number.

It is not a de Polignac number, because 21952817 - 2¹⁰ = 21951793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21952811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28583 + ... + 29340.

It is an arithmetic number, because the mean of its divisors is an integer number (5502780).

Almost surely, 2^21952817 is an apocalyptic number.

It is an amenable number.

21952817 is a deficient number, since it is larger than the sum of its proper divisors (58303).

21952817 is an equidigital number, since it uses as much as digits as its factorization.

21952817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58302.

The product of its digits is 10080, while the sum is 35.

The square root of 21952817 is about 4685.3833354380. The cubic root of 21952817 is about 280.0034735964.

The spelling of 21952817 in words is "twenty-one million, nine hundred fifty-two thousand, eight hundred seventeen".