21286044 has 48 divisors (see below), whose sum is σ = 59435040. Its totient is φ = 6549120.

The previous prime is 21286039. The next prime is 21286051. The reversal of 21286044 is 44068212.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21285999 and 21286017.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 6177 + ... + 8984.

It is an arithmetic number, because the mean of its divisors is an integer number (1238230).

Almost surely, 2^21286044 is an apocalyptic number.

It is an amenable number.

21286044 is an abundant number, since it is smaller than the sum of its proper divisors (38148996).

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

21286044 is a wasteful number, since it uses less digits than its factorization.

21286044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15187 (or 15179 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 21286044 is about 4613.6800929410. The cubic root of 21286044 is about 277.1394294299.

The spelling of 21286044 in words is "twenty-one million, two hundred eighty-six thousand, forty-four".