21786116 has 12 divisors (see below), whose sum is σ = 41591760. Its totient is φ = 9902760.

The previous prime is 21786113. The next prime is 21786133. The reversal of 21786116 is 61168712.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21786113) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 247526 + ... + 247613.

It is an arithmetic number, because the mean of its divisors is an integer number (3465980).

Almost surely, 2^21786116 is an apocalyptic number.

It is an amenable number.

21786116 is a deficient number, since it is larger than the sum of its proper divisors (19805644).

21786116 is a wasteful number, since it uses less digits than its factorization.

21786116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495154 (or 495152 counting only the distinct ones).

The product of its digits is 4032, while the sum is 32.

The square root of 21786116 is about 4667.5599621215. The cubic root of 21786116 is about 279.2929268429.

The spelling of 21786116 in words is "twenty-one million, seven hundred eighty-six thousand, one hundred sixteen".