21859486 has 16 divisors (see below), whose sum is σ = 35906688. Its totient is φ = 9898200.

The previous prime is 21859483. The next prime is 21859507. The reversal of 21859486 is 68495812.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21859483) 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 7 ways as a sum of consecutive naturals, for example, 4471 + ... + 7981.

It is an arithmetic number, because the mean of its divisors is an integer number (2244168).

Almost surely, 2^21859486 is an apocalyptic number.

21859486 is a deficient number, since it is larger than the sum of its proper divisors (14047202).

21859486 is a wasteful number, since it uses less digits than its factorization.

21859486 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3807.

The product of its digits is 138240, while the sum is 43.

The square root of 21859486 is about 4675.4129229406. The cubic root of 21859486 is about 279.6061043023.

The spelling of 21859486 in words is "twenty-one million, eight hundred fifty-nine thousand, four hundred eighty-six".