21256886 has 24 divisors (see below), whose sum is σ = 38293056. Its totient is φ = 8814960.

The previous prime is 21256867. The next prime is 21256909. The reversal of 21256886 is 68865212.

21256886 is nontrivially palindromic in base 6.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 461 + ... + 6536.

It is an arithmetic number, because the mean of its divisors is an integer number (1595544).

Almost surely, 2^21256886 is an apocalyptic number.

21256886 is a deficient number, since it is larger than the sum of its proper divisors (17036170).

21256886 is a wasteful number, since it uses less digits than its factorization.

21256886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7044 (or 7037 counting only the distinct ones).

The product of its digits is 46080, while the sum is 38.

The square root of 21256886 is about 4610.5190597155. The cubic root of 21256886 is about 277.0128281061.

The spelling of 21256886 in words is "twenty-one million, two hundred fifty-six thousand, eight hundred eighty-six".