21266055 has 24 divisors (see below), whose sum is σ = 37234080. Its totient is φ = 11227200.

The previous prime is 21266051. The next prime is 21266059. The reversal of 21266055 is 55066212.

It is an interprime number because it is at equal distance from previous prime (21266051) and next prime (21266059).

It is not a de Polignac number, because 21266055 - 2² = 21266051 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21266051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2206 + ... + 6884.

It is an arithmetic number, because the mean of its divisors is an integer number (1551420).

Almost surely, 2^21266055 is an apocalyptic number.

21266055 is a deficient number, since it is larger than the sum of its proper divisors (15968025).

21266055 is a wasteful number, since it uses less digits than its factorization.

21266055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4791 (or 4788 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 21266055 is about 4611.5133090993. The cubic root of 21266055 is about 277.0526515232.

The spelling of 21266055 in words is "twenty-one million, two hundred sixty-six thousand, fifty-five".