21847959 has 12 divisors (see below), whose sum is σ = 36066576. Its totient is φ = 12484512.

The previous prime is 21847939. The next prime is 21847961. The reversal of 21847959 is 95974812.

It is not a de Polignac number, because 21847959 - 2⁵ = 21847927 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21847909) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 173334 + ... + 173459.

It is an arithmetic number, because the mean of its divisors is an integer number (3005548).

Almost surely, 2^21847959 is an apocalyptic number.

21847959 is a deficient number, since it is larger than the sum of its proper divisors (14218617).

21847959 is a wasteful number, since it uses less digits than its factorization.

21847959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346806 (or 346803 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 21847959 is about 4674.1800350436. The cubic root of 21847959 is about 279.5569481258.

The spelling of 21847959 in words is "twenty-one million, eight hundred forty-seven thousand, nine hundred fifty-nine".