21338371 has 4 divisors (see below), whose sum is σ = 21549744. Its totient is φ = 21127000.

The previous prime is 21338357. The next prime is 21338431. The reversal of 21338371 is 17383312.

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

It is a cyclic number.

It is not a de Polignac number, because 21338371 - 2⁷ = 21338243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21338321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105535 + ... + 105736.

It is an arithmetic number, because the mean of its divisors is an integer number (5387436).

Almost surely, 2^21338371 is an apocalyptic number.

21338371 is a deficient number, since it is larger than the sum of its proper divisors (211373).

21338371 is a wasteful number, since it uses less digits than its factorization.

21338371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211372.

The product of its digits is 3024, while the sum is 28.

The square root of 21338371 is about 4619.3474647400. The cubic root of 21338371 is about 277.3663387907.

The spelling of 21338371 in words is "twenty-one million, three hundred thirty-eight thousand, three hundred seventy-one".