21124066 has 4 divisors (see below), whose sum is σ = 31686102. Its totient is φ = 10562032.

The previous prime is 21124063. The next prime is 21124069. The reversal of 21124066 is 66042112.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21124063) and next prime (21124069).

It can be written as a sum of positive squares in only one way, i.e., 19989841 + 1134225 = 4471^2 + 1065^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21124063) 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 as a sum of consecutive naturals, namely, 5281015 + ... + 5281018.

Almost surely, 2^21124066 is an apocalyptic number.

21124066 is a deficient number, since it is larger than the sum of its proper divisors (10562036).

21124066 is a wasteful number, since it uses less digits than its factorization.

21124066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10562035.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 21124066 is about 4596.0924707843. The cubic root of 21124066 is about 276.4346665603.

Adding to 21124066 its reverse (66042112), we get a palindrome (87166178).

It can be divided in two parts, 211240 and 66, that multiplied together give a triangular number (13941840 = T₅₂₈₀).

The spelling of 21124066 in words is "twenty-one million, one hundred twenty-four thousand, sixty-six".