21319138 has 4 divisors (see below), whose sum is σ = 31978710. Its totient is φ = 10659568.

The previous prime is 21319127. The next prime is 21319169. The reversal of 21319138 is 83191312.

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., 20403289 + 915849 = 4517^2 + 957^2 .

It is a plaindrome in base 13.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5329783 + ... + 5329786.

Almost surely, 2^21319138 is an apocalyptic number.

21319138 is a deficient number, since it is larger than the sum of its proper divisors (10659572).

21319138 is a wasteful number, since it uses less digits than its factorization.

21319138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10659571.

The product of its digits is 1296, while the sum is 28.

The square root of 21319138 is about 4617.2652078909. The cubic root of 21319138 is about 277.2829805009.

The spelling of 21319138 in words is "twenty-one million, three hundred nineteen thousand, one hundred thirty-eight".