21847955 has 4 divisors (see below), whose sum is σ = 26217552. Its totient is φ = 17478360.

The previous prime is 21847939. The next prime is 21847961. The reversal of 21847955 is 55974812.

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

It is not a de Polignac number, because 21847955 - 2⁴ = 21847939 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2184791 + ... + 2184800.

It is an arithmetic number, because the mean of its divisors is an integer number (6554388).

Almost surely, 2^21847955 is an apocalyptic number.

21847955 is a deficient number, since it is larger than the sum of its proper divisors (4369597).

21847955 is an equidigital number, since it uses as much as digits as its factorization.

21847955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4369596.

The product of its digits is 100800, while the sum is 41.

The square root of 21847955 is about 4674.1796071610. The cubic root of 21847955 is about 279.5569310651.

The spelling of 21847955 in words is "twenty-one million, eight hundred forty-seven thousand, nine hundred fifty-five".