21052417 has 4 divisors (see below), whose sum is σ = 21062080. Its totient is φ = 21042756.

The previous prime is 21052411. The next prime is 21052469. The reversal of 21052417 is 71425012.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21052417 - 2²³ = 12663809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21052411) 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, 148 + ... + 6490.

It is an arithmetic number, because the mean of its divisors is an integer number (5265520).

Almost surely, 2^21052417 is an apocalyptic number.

It is an amenable number.

21052417 is a deficient number, since it is larger than the sum of its proper divisors (9663).

21052417 is an equidigital number, since it uses as much as digits as its factorization.

21052417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9662.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21052417 is about 4588.2912941530. The cubic root of 21052417 is about 276.1217737866.

Adding to 21052417 its reverse (71425012), we get a palindrome (92477429).

The spelling of 21052417 in words is "twenty-one million, fifty-two thousand, four hundred seventeen".