21889479 has 4 divisors (see below), whose sum is σ = 29185976. Its totient is φ = 14592984.

The previous prime is 21889453. The next prime is 21889487. The reversal of 21889479 is 97498812.

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

It is not a de Polignac number, because 21889479 - 2⁵ = 21889447 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 (21889429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3648244 + ... + 3648249.

It is an arithmetic number, because the mean of its divisors is an integer number (7296494).

Almost surely, 2^21889479 is an apocalyptic number.

21889479 is a deficient number, since it is larger than the sum of its proper divisors (7296497).

21889479 is an equidigital number, since it uses as much as digits as its factorization.

21889479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7296496.

The product of its digits is 290304, while the sum is 48.

The square root of 21889479 is about 4678.6193476281. The cubic root of 21889479 is about 279.7339266625.

The spelling of 21889479 in words is "twenty-one million, eight hundred eighty-nine thousand, four hundred seventy-nine".