21260216 has 8 divisors (see below), whose sum is σ = 39862920. Its totient is φ = 10630104.

The previous prime is 21260209. The next prime is 21260227. The reversal of 21260216 is 61206212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1328756 + ... + 1328771.

It is an arithmetic number, because the mean of its divisors is an integer number (4982865).

Almost surely, 2^21260216 is an apocalyptic number.

It is an amenable number.

21260216 is a deficient number, since it is larger than the sum of its proper divisors (18602704).

21260216 is a wasteful number, since it uses less digits than its factorization.

21260216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2657533 (or 2657529 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21260216 is about 4610.8801762787. The cubic root of 21260216 is about 277.0272925099.

Adding to 21260216 its reverse (61206212), we get a palindrome (82466428).

The spelling of 21260216 in words is "twenty-one million, two hundred sixty thousand, two hundred sixteen".