21814042 has 4 divisors (see below), whose sum is σ = 32721066. Its totient is φ = 10907020.

The previous prime is 21814021. The next prime is 21814069. The reversal of 21814042 is 24041812.

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

It can be written as a sum of positive squares in only one way, i.e., 14891881 + 6922161 = 3859^2 + 2631^2 .

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 an unprimeable number.

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 as a sum of consecutive naturals, namely, 5453509 + ... + 5453512.

Almost surely, 2^21814042 is an apocalyptic number.

21814042 is a deficient number, since it is larger than the sum of its proper divisors (10907024).

21814042 is a wasteful number, since it uses less digits than its factorization.

21814042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10907023.

The product of its (nonzero) digits is 512, while the sum is 22.

The square root of 21814042 is about 4670.5505028851. The cubic root of 21814042 is about 279.4122108263.

Adding to 21814042 its reverse (24041812), we get a palindrome (45855854).

The spelling of 21814042 in words is "twenty-one million, eight hundred fourteen thousand, forty-two".