21052685 has 8 divisors (see below), whose sum is σ = 25509120. Its totient is φ = 16678224.

The previous prime is 21052679. The next prime is 21052687. The reversal of 21052685 is 58625012.

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

It is a cyclic number.

It is not a de Polignac number, because 21052685 - 2⁶ = 21052621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19925 + ... + 20954.

It is an arithmetic number, because the mean of its divisors is an integer number (3188640).

Almost surely, 2^21052685 is an apocalyptic number.

It is an amenable number.

21052685 is a deficient number, since it is larger than the sum of its proper divisors (4456435).

21052685 is a wasteful number, since it uses less digits than its factorization.

21052685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40987.

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 21052685 is about 4588.3204988318. The cubic root of 21052685 is about 276.1229454703.

Adding to 21052685 its reverse (58625012), we get a palindrome (79677697).

The spelling of 21052685 in words is "twenty-one million, fifty-two thousand, six hundred eighty-five".