21252635 has 8 divisors (see below), whose sum is σ = 27003456. Its totient is φ = 16001920.

The previous prime is 21252617. The next prime is 21252653. The reversal of 21252635 is 53625212.

It is an interprime number because it is at equal distance from previous prime (21252617) and next prime (21252653).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21252635 - 2⁶ = 21252571 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124931 + ... + 125100.

It is an arithmetic number, because the mean of its divisors is an integer number (3375432).

Almost surely, 2^21252635 is an apocalyptic number.

21252635 is a deficient number, since it is larger than the sum of its proper divisors (5750821).

21252635 is a wasteful number, since it uses less digits than its factorization.

21252635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250053.

The product of its digits is 3600, while the sum is 26.

The square root of 21252635 is about 4610.0580256652. The cubic root of 21252635 is about 276.9943609916.

Adding to 21252635 its reverse (53625212), we get a palindrome (74877847).

The spelling of 21252635 in words is "twenty-one million, two hundred fifty-two thousand, six hundred thirty-five".