21442186 has 8 divisors (see below), whose sum is σ = 32304420. Its totient is φ = 10674048.

The previous prime is 21442163. The next prime is 21442229. The reversal of 21442186 is 68124412.

It can be written as a sum of positive squares in 2 ways, for example, as 18326961 + 3115225 = 4281^2 + 1765^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a plaindrome in base 13.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22951 + ... + 23866.

Almost surely, 2^21442186 is an apocalyptic number.

21442186 is a deficient number, since it is larger than the sum of its proper divisors (10862234).

21442186 is a wasteful number, since it uses less digits than its factorization.

21442186 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47048.

The product of its digits is 3072, while the sum is 28.

The square root of 21442186 is about 4630.5708071468. The cubic root of 21442186 is about 277.8154236030.

Adding to 21442186 its reverse (68124412), we get a palindrome (89566598).

The spelling of 21442186 in words is "twenty-one million, four hundred forty-two thousand, one hundred eighty-six".