21745411 has 4 divisors (see below), whose sum is σ = 21757824. Its totient is φ = 21733000.

The previous prime is 21745403. The next prime is 21745417. The reversal of 21745411 is 11454712.

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 21745411 - 2³ = 21745403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21745417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3040 + ... + 7261.

It is an arithmetic number, because the mean of its divisors is an integer number (5439456).

Almost surely, 2^21745411 is an apocalyptic number.

21745411 is a deficient number, since it is larger than the sum of its proper divisors (12413).

21745411 is a wasteful number, since it uses less digits than its factorization.

21745411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12412.

The product of its digits is 1120, while the sum is 25.

The square root of 21745411 is about 4663.1975081482. The cubic root of 21745411 is about 279.1188755298.

The spelling of 21745411 in words is "twenty-one million, seven hundred forty-five thousand, four hundred eleven".