21856075 has 12 divisors (see below), whose sum is σ = 27763848. Its totient is φ = 17057600.

The previous prime is 21856069. The next prime is 21856129. The reversal of 21856075 is 57065812.

It is not a de Polignac number, because 21856075 - 2¹⁷ = 21725003 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21856075.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9637 + ... + 11686.

It is an arithmetic number, because the mean of its divisors is an integer number (2313654).

Almost surely, 2^21856075 is an apocalyptic number.

21856075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21856075 is a deficient number, since it is larger than the sum of its proper divisors (5907773).

21856075 is a wasteful number, since it uses less digits than its factorization.

21856075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21374 (or 21369 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 34.

The square root of 21856075 is about 4675.0481280945. The cubic root of 21856075 is about 279.5915601050.

The spelling of 21856075 in words is "twenty-one million, eight hundred fifty-six thousand, seventy-five".