21814471 has 4 divisors (see below), whose sum is σ = 24930832. Its totient is φ = 18698112.

The previous prime is 21814447. The next prime is 21814487. The reversal of 21814471 is 17441812.

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 21814471 - 2⁷ = 21814343 is a prime.

It is a super-3 number, since 3×21814471³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21814171) 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, 1558170 + ... + 1558183.

It is an arithmetic number, because the mean of its divisors is an integer number (6232708).

Almost surely, 2^21814471 is an apocalyptic number.

21814471 is a deficient number, since it is larger than the sum of its proper divisors (3116361).

21814471 is an equidigital number, since it uses as much as digits as its factorization.

21814471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3116360.

The product of its digits is 1792, while the sum is 28.

The square root of 21814471 is about 4670.5964287230. The cubic root of 21814471 is about 279.4140424760.

The spelling of 21814471 in words is "twenty-one million, eight hundred fourteen thousand, four hundred seventy-one".