21889471 has 4 divisors (see below), whose sum is σ = 21898944. Its totient is φ = 21880000.

The previous prime is 21889453. The next prime is 21889487. The reversal of 21889471 is 17498812.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21889471 - 2¹¹ = 21887423 is a prime.

It is a super-3 number, since 3×21889471³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21889871) 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, 1266 + ... + 6736.

It is an arithmetic number, because the mean of its divisors is an integer number (5474736).

Almost surely, 2^21889471 is an apocalyptic number.

21889471 is a deficient number, since it is larger than the sum of its proper divisors (9473).

21889471 is an equidigital number, since it uses as much as digits as its factorization.

21889471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9472.

The product of its digits is 32256, while the sum is 40.

The square root of 21889471 is about 4678.6184926749. The cubic root of 21889471 is about 279.7338925842.

The spelling of 21889471 in words is "twenty-one million, eight hundred eighty-nine thousand, four hundred seventy-one".