21849147 has 6 divisors (see below), whose sum is σ = 31559892. Its totient is φ = 14566092.

The previous prime is 21849137. The next prime is 21849161. The reversal of 21849147 is 74194812.

It is not a de Polignac number, because 21849147 - 2⁶ = 21849083 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21849127) 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 5 ways as a sum of consecutive naturals, for example, 1213833 + ... + 1213850.

It is an arithmetic number, because the mean of its divisors is an integer number (5259982).

Almost surely, 2^21849147 is an apocalyptic number.

21849147 is a deficient number, since it is larger than the sum of its proper divisors (9710745).

21849147 is a wasteful number, since it uses less digits than its factorization.

21849147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2427689 (or 2427686 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 21849147 is about 4674.3071144288. The cubic root of 21849147 is about 279.5620150772.

The spelling of 21849147 in words is "twenty-one million, eight hundred forty-nine thousand, one hundred forty-seven".