21341647 has 4 divisors (see below), whose sum is σ = 22597056. Its totient is φ = 20086240.

The previous prime is 21341629. The next prime is 21341659. The reversal of 21341647 is 74614312.

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 21341647 - 2¹¹ = 21339599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21341627) 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, 627679 + ... + 627712.

It is an arithmetic number, because the mean of its divisors is an integer number (5649264).

Almost surely, 2^21341647 is an apocalyptic number.

21341647 is a deficient number, since it is larger than the sum of its proper divisors (1255409).

21341647 is a wasteful number, since it uses less digits than its factorization.

21341647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1255408.

The product of its digits is 4032, while the sum is 28.

The square root of 21341647 is about 4619.7020466692. The cubic root of 21341647 is about 277.3805324020.

Adding to 21341647 its reverse (74614312), we get a palindrome (95955959).

The spelling of 21341647 in words is "twenty-one million, three hundred forty-one thousand, six hundred forty-seven".