21255116 has 12 divisors (see below), whose sum is σ = 37257360. Its totient is φ = 10610160.

The previous prime is 21255107. The next prime is 21255127. The reversal of 21255116 is 61155212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21255091 and 21255100.

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 3 ways as a sum of consecutive naturals, for example, 1376 + ... + 6663.

It is an arithmetic number, because the mean of its divisors is an integer number (3104780).

Almost surely, 2^21255116 is an apocalyptic number.

It is an amenable number.

21255116 is a deficient number, since it is larger than the sum of its proper divisors (16002244).

21255116 is a wasteful number, since it uses less digits than its factorization.

21255116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8704 (or 8702 counting only the distinct ones).

The product of its digits is 600, while the sum is 23.

The square root of 21255116 is about 4610.3271033626. The cubic root of 21255116 is about 277.0051392044.

The spelling of 21255116 in words is "twenty-one million, two hundred fifty-five thousand, one hundred sixteen".