21260655 has 24 divisors (see below), whose sum is σ = 39687648. Its totient is φ = 10466496.

The previous prime is 21260651. The next prime is 21260663. The reversal of 21260655 is 55606212.

21260655 is a `hidden beast` number, since 2 + 1 + 2 + 6 + 0 + 655 = 666.

It is not a de Polignac number, because 21260655 - 2² = 21260651 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21260651) 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, 17587 + ... + 18756.

It is an arithmetic number, because the mean of its divisors is an integer number (1653652).

Almost surely, 2^21260655 is an apocalyptic number.

21260655 is a deficient number, since it is larger than the sum of its proper divisors (18426993).

21260655 is a wasteful number, since it uses less digits than its factorization.

21260655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36367 (or 36364 counting only the distinct ones).

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

The square root of 21260655 is about 4610.9277808268. The cubic root of 21260655 is about 277.0291992661.

Adding to 21260655 its reverse (55606212), we get a palindrome (76866867).

The spelling of 21260655 in words is "twenty-one million, two hundred sixty thousand, six hundred fifty-five".