21052599 has 4 divisors (see below), whose sum is σ = 28070136. Its totient is φ = 14035064.

The previous prime is 21052597. The next prime is 21052609. The reversal of 21052599 is 99525012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21052599 - 2¹ = 21052597 is a prime.

It is a super-3 number, since 3×21052599³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052597) 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 3 ways as a sum of consecutive naturals, for example, 3508764 + ... + 3508769.

It is an arithmetic number, because the mean of its divisors is an integer number (7017534).

Almost surely, 2^21052599 is an apocalyptic number.

21052599 is a deficient number, since it is larger than the sum of its proper divisors (7017537).

21052599 is an equidigital number, since it uses as much as digits as its factorization.

21052599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7017536.

The product of its (nonzero) digits is 8100, while the sum is 33.

The square root of 21052599 is about 4588.3111272014. The cubic root of 21052599 is about 276.1225694833.

The spelling of 21052599 in words is "twenty-one million, fifty-two thousand, five hundred ninety-nine".