21445711 has 4 divisors (see below), whose sum is σ = 24509392. Its totient is φ = 18382032.

The previous prime is 21445673. The next prime is 21445717. The reversal of 21445711 is 11754412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21445711 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 (21445717) 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, 1531830 + ... + 1531843.

It is an arithmetic number, because the mean of its divisors is an integer number (6127348).

Almost surely, 2^21445711 is an apocalyptic number.

21445711 is a deficient number, since it is larger than the sum of its proper divisors (3063681).

21445711 is an equidigital number, since it uses as much as digits as its factorization.

21445711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3063680.

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

The square root of 21445711 is about 4630.9514141265. The cubic root of 21445711 is about 277.8306466421.

The spelling of 21445711 in words is "twenty-one million, four hundred forty-five thousand, seven hundred eleven".