21344147 has 4 divisors (see below), whose sum is σ = 23284536. Its totient is φ = 19403760.

The previous prime is 21344131. The next prime is 21344159. The reversal of 21344147 is 74144312.

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 21344147 - 2⁴ = 21344131 is a prime.

It is a super-2 number, since 2×21344147² = 911145222315218, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21344117) 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, 970178 + ... + 970199.

It is an arithmetic number, because the mean of its divisors is an integer number (5821134).

Almost surely, 2^21344147 is an apocalyptic number.

21344147 is a deficient number, since it is larger than the sum of its proper divisors (1940389).

21344147 is a wasteful number, since it uses less digits than its factorization.

21344147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1940388.

The product of its digits is 2688, while the sum is 26.

The square root of 21344147 is about 4619.9726189665. The cubic root of 21344147 is about 277.3913629353.

Adding to 21344147 its reverse (74144312), we get a palindrome (95488459).

The spelling of 21344147 in words is "twenty-one million, three hundred forty-four thousand, one hundred forty-seven".