21626216 has 16 divisors (see below), whose sum is σ = 40676640. Its totient is φ = 10779120.

The previous prime is 21626207. The next prime is 21626219. The reversal of 21626216 is 61262612.

It is not an unprimeable number, because it can be changed into a prime (21626219) 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, 1436 + ... + 6731.

It is an arithmetic number, because the mean of its divisors is an integer number (2542290).

Almost surely, 2^21626216 is an apocalyptic number.

It is an amenable number.

21626216 is a deficient number, since it is larger than the sum of its proper divisors (19050424).

21626216 is a wasteful number, since it uses less digits than its factorization.

21626216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8504 (or 8500 counting only the distinct ones).

The product of its digits is 1728, while the sum is 26.

The square root of 21626216 is about 4650.3995527266. The cubic root of 21626216 is about 278.6079547359.

Adding to 21626216 its reverse (61262612), we get a palindrome (82888828).

The spelling of 21626216 in words is "twenty-one million, six hundred twenty-six thousand, two hundred sixteen".