21052239 has 32 divisors (see below), whose sum is σ = 32405184. Its totient is φ = 12042240.

The previous prime is 21052219. The next prime is 21052243. The reversal of 21052239 is 93225012.

It is not a de Polignac number, because 21052239 - 2⁷ = 21052111 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 74779 + ... + 75059.

It is an arithmetic number, because the mean of its divisors is an integer number (1012662).

Almost surely, 2^21052239 is an apocalyptic number.

21052239 is a deficient number, since it is larger than the sum of its proper divisors (11352945).

21052239 is a wasteful number, since it uses less digits than its factorization.

21052239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 21052239 is about 4588.2718969128. The cubic root of 21052239 is about 276.1209955733.

The spelling of 21052239 in words is "twenty-one million, fifty-two thousand, two hundred thirty-nine".