21262066 has 16 divisors (see below), whose sum is σ = 37068480. Its totient is φ = 8957520.

The previous prime is 21262061. The next prime is 21262069. The reversal of 21262066 is 66026212.

It is a self number, because there is not a number n which added to its sum of digits gives 21262066.

It is not an unprimeable number, because it can be changed into a prime (21262061) 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 7 ways as a sum of consecutive naturals, for example, 12045 + ... + 13696.

It is an arithmetic number, because the mean of its divisors is an integer number (2316780).

Almost surely, 2^21262066 is an apocalyptic number.

21262066 is a deficient number, since it is larger than the sum of its proper divisors (15806414).

21262066 is a wasteful number, since it uses less digits than its factorization.

21262066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25809.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 21262066 is about 4611.0807843715. The cubic root of 21262066 is about 277.0353276372.

Adding to 21262066 its reverse (66026212), we get a palindrome (87288278).

It can be divided in two parts, 2126206 and 6, that added together give a palindrome (2126212).

The spelling of 21262066 in words is "twenty-one million, two hundred sixty-two thousand, sixty-six".