21266685 has 32 divisors (see below), whose sum is σ = 41247360. Its totient is φ = 10310400.

The previous prime is 21266669. The next prime is 21266731. The reversal of 21266685 is 58666212.

It is not a de Polignac number, because 21266685 - 2⁴ = 21266669 is a prime.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 5676 + ... + 8645.

It is an arithmetic number, because the mean of its divisors is an integer number (1288980).

Almost surely, 2^21266685 is an apocalyptic number.

It is an amenable number.

21266685 is a deficient number, since it is larger than the sum of its proper divisors (19980675).

21266685 is a wasteful number, since it uses less digits than its factorization.

21266685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14346 (or 14340 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 21266685 is about 4611.5816158884. The cubic root of 21266685 is about 277.0553873612.

The spelling of 21266685 in words is "twenty-one million, two hundred sixty-six thousand, six hundred eighty-five".