21359886 has 16 divisors (see below), whose sum is σ = 42768000. Its totient is φ = 7111928.

The previous prime is 21359879. The next prime is 21359887. The reversal of 21359886 is 68895312.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21359887) 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, 6565 + ... + 9263.

It is an arithmetic number, because the mean of its divisors is an integer number (2673000).

Almost surely, 2^21359886 is an apocalyptic number.

21359886 is an abundant number, since it is smaller than the sum of its proper divisors (21408114).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21359886 is a wasteful number, since it uses less digits than its factorization.

21359886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4023.

The product of its digits is 103680, while the sum is 42.

The square root of 21359886 is about 4621.6756701439. The cubic root of 21359886 is about 277.4595282264.

It can be divided in two parts, 2135 and 9886, that added together give a palindrome (12021).

The spelling of 21359886 in words is "twenty-one million, three hundred fifty-nine thousand, eight hundred eighty-six".