21116066 has 16 divisors (see below), whose sum is σ = 33143040. Its totient is φ = 10079520.

The previous prime is 21116063. The next prime is 21116099. The reversal of 21116066 is 66061112.

It is not an unprimeable number, because it can be changed into a prime (21116063) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1115 + ... + 6593.

It is an arithmetic number, because the mean of its divisors is an integer number (2071440).

Almost surely, 2^21116066 is an apocalyptic number.

21116066 is a deficient number, since it is larger than the sum of its proper divisors (12026974).

21116066 is a wasteful number, since it uses less digits than its factorization.

21116066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5569.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21116066 is about 4595.2220838606. Note that the first 3 decimals coincide. The cubic root of 21116066 is about 276.3997655053.

Adding to 21116066 its reverse (66061112), we get a palindrome (87177178).

It can be divided in two parts, 211160 and 66, that multiplied together give a triangular number (13936560 = T₅₂₇₉).

The spelling of 21116066 in words is "twenty-one million, one hundred sixteen thousand, sixty-six".