21286316 has 24 divisors (see below), whose sum is σ = 39518304. Its totient is φ = 10010880.

The previous prime is 21286303. The next prime is 21286351. The reversal of 21286316 is 61368212.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3716 + ... + 7508.

It is an arithmetic number, because the mean of its divisors is an integer number (1646596).

Almost surely, 2^21286316 is an apocalyptic number.

It is an amenable number.

21286316 is a deficient number, since it is larger than the sum of its proper divisors (18231988).

21286316 is a wasteful number, since it uses less digits than its factorization.

21286316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3881 (or 3879 counting only the distinct ones).

The product of its digits is 3456, while the sum is 29.

The square root of 21286316 is about 4613.7095703999. The cubic root of 21286316 is about 277.1406098842.

The spelling of 21286316 in words is "twenty-one million, two hundred eighty-six thousand, three hundred sixteen".