21066562 has 24 divisors (see below), whose sum is σ = 35143920. Its totient is φ = 9392280.

The previous prime is 21066527. The next prime is 21066581. The reversal of 21066562 is 26566012.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21066562.

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, 151489 + ... + 151627.

It is an arithmetic number, because the mean of its divisors is an integer number (1464330).

Almost surely, 2^21066562 is an apocalyptic number.

21066562 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21066562 is a deficient number, since it is larger than the sum of its proper divisors (14077358).

21066562 is a wasteful number, since it uses less digits than its factorization.

21066562 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318 (or 235 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 21066562 is about 4589.8324588159. The cubic root of 21066562 is about 276.1836014945.

It can be divided in two parts, 2106 and 6562, that added together give a palindrome (8668).

The spelling of 21066562 in words is "twenty-one million, sixty-six thousand, five hundred sixty-two".