21256966 has 8 divisors (see below), whose sum is σ = 32064120. Its totient is φ = 10568928.

The previous prime is 21256931. The next prime is 21256997. The reversal of 21256966 is 66965212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29331 + ... + 30046.

It is an arithmetic number, because the mean of its divisors is an integer number (4008015).

Almost surely, 2^21256966 is an apocalyptic number.

21256966 is a deficient number, since it is larger than the sum of its proper divisors (10807154).

21256966 is a wasteful number, since it uses less digits than its factorization.

21256966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59558.

The product of its digits is 38880, while the sum is 37.

The square root of 21256966 is about 4610.5277355201. The cubic root of 21256966 is about 277.0131756169.

It can be divided in two parts, 21256 and 966, that added together give a palindrome (22222).

The spelling of 21256966 in words is "twenty-one million, two hundred fifty-six thousand, nine hundred sixty-six".