21052413 has 16 divisors (see below), whose sum is σ = 31915840. Its totient is φ = 13707792.

The previous prime is 21052411. The next prime is 21052469. The reversal of 21052413 is 31425012.

It is not a de Polignac number, because 21052413 - 2¹ = 21052411 is a prime.

It is a Duffinian number.

It is a congruent 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 15 ways as a sum of consecutive naturals, for example, 7906 + ... + 10227.

It is an arithmetic number, because the mean of its divisors is an integer number (1994740).

Almost surely, 2^21052413 is an apocalyptic number.

It is an amenable number.

21052413 is a deficient number, since it is larger than the sum of its proper divisors (10863427).

21052413 is a wasteful number, since it uses less digits than its factorization.

21052413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18185 (or 18179 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21052413 is about 4588.2908582608. The cubic root of 21052413 is about 276.1217562987.

Adding to 21052413 its reverse (31425012), we get a palindrome (52477425).

The spelling of 21052413 in words is "twenty-one million, fifty-two thousand, four hundred thirteen".