21199138 has 4 divisors (see below), whose sum is σ = 31798710. Its totient is φ = 10599568.

The previous prime is 21199121. The next prime is 21199141. The reversal of 21199138 is 83199112.

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., 18774889 + 2424249 = 4333^2 + 1557^2 .

It is an unprimeable number.

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, 5299783 + ... + 5299786.

Almost surely, 2^21199138 is an apocalyptic number.

21199138 is a deficient number, since it is larger than the sum of its proper divisors (10599572).

21199138 is a wasteful number, since it uses less digits than its factorization.

21199138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10599571.

The product of its digits is 3888, while the sum is 34.

The square root of 21199138 is about 4604.2521651187. The cubic root of 21199138 is about 276.7617495482.

The spelling of 21199138 in words is "twenty-one million, one hundred ninety-nine thousand, one hundred thirty-eight".