21270766 has 32 divisors (see below), whose sum is σ = 36990720. Its totient is φ = 9072000.

The previous prime is 21270763. The next prime is 21270773. The reversal of 21270766 is 66707212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21270763) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 62950 + ... + 63286.

It is an arithmetic number, because the mean of its divisors is an integer number (1155960).

Almost surely, 2^21270766 is an apocalyptic number.

21270766 is a deficient number, since it is larger than the sum of its proper divisors (15719954).

21270766 is a wasteful number, since it uses less digits than its factorization.

21270766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 21270766 is about 4612.0240675868. The cubic root of 21270766 is about 277.0731082036.

Adding to 21270766 its reverse (66707212), we get a palindrome (87977978).

The spelling of 21270766 in words is "twenty-one million, two hundred seventy thousand, seven hundred sixty-six".