21896559 has 12 divisors (see below), whose sum is σ = 31743816. Its totient is φ = 14544432.

The previous prime is 21896543. The next prime is 21896597. The reversal of 21896559 is 95569812.

21896559 is a `hidden beast` number, since 2 + 1 + 8 + 96 + 559 = 666.

It is not a de Polignac number, because 21896559 - 2⁴ = 21896543 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21897559) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1752 + ... + 6845.

It is an arithmetic number, because the mean of its divisors is an integer number (2645318).

Almost surely, 2^21896559 is an apocalyptic number.

21896559 is a deficient number, since it is larger than the sum of its proper divisors (9847257).

21896559 is a wasteful number, since it uses less digits than its factorization.

21896559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8886 (or 8883 counting only the distinct ones).

The product of its digits is 194400, while the sum is 45.

The square root of 21896559 is about 4679.3759199278. The cubic root of 21896559 is about 279.7640827436.

It can be divided in two parts, 218965 and 59, that added together give a square (219024 = 468²).

The spelling of 21896559 in words is "twenty-one million, eight hundred ninety-six thousand, five hundred fifty-nine".