21323741 has 4 divisors (see below), whose sum is σ = 21336000. Its totient is φ = 21311484.

The previous prime is 21323717. The next prime is 21323747. The reversal of 21323741 is 14732312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21323741 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 (21323747) 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, 2981 + ... + 7178.

It is an arithmetic number, because the mean of its divisors is an integer number (5334000).

Almost surely, 2^21323741 is an apocalyptic number.

It is an amenable number.

21323741 is a deficient number, since it is larger than the sum of its proper divisors (12259).

21323741 is a wasteful number, since it uses less digits than its factorization.

21323741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12258.

The product of its digits is 1008, while the sum is 23.

The square root of 21323741 is about 4617.7636362205. The cubic root of 21323741 is about 277.3029350555.

The spelling of 21323741 in words is "twenty-one million, three hundred twenty-three thousand, seven hundred forty-one".