21255068 has 6 divisors (see below), whose sum is σ = 37196376. Its totient is φ = 10627532.

The previous prime is 21255061. The next prime is 21255077. The reversal of 21255068 is 86055212.

It is a self number, because there is not a number n which added to its sum of digits gives 21255068.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255061) by changing a digit.

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 as a sum of consecutive naturals, namely, 2656880 + ... + 2656887.

It is an arithmetic number, because the mean of its divisors is an integer number (6199396).

Almost surely, 2^21255068 is an apocalyptic number.

It is an amenable number.

21255068 is a deficient number, since it is larger than the sum of its proper divisors (15941308).

21255068 is a wasteful number, since it uses less digits than its factorization.

21255068 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5313771 (or 5313769 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 21255068 is about 4610.3218976553. The cubic root of 21255068 is about 277.0049306859.

The spelling of 21255068 in words is "twenty-one million, two hundred fifty-five thousand, sixty-eight".