21849291 has 16 divisors (see below), whose sum is σ = 32442400. Its totient is φ = 14533344.

The previous prime is 21849283. The next prime is 21849307. The reversal of 21849291 is 19294812.

It is not a de Polignac number, because 21849291 - 2³ = 21849283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21849491) 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 15 ways as a sum of consecutive naturals, for example, 19905 + ... + 20973.

It is an arithmetic number, because the mean of its divisors is an integer number (2027650).

Almost surely, 2^21849291 is an apocalyptic number.

21849291 is a deficient number, since it is larger than the sum of its proper divisors (10593109).

21849291 is a wasteful number, since it uses less digits than its factorization.

21849291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1835 (or 1829 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 21849291 is about 4674.3225177559. The cubic root of 21849291 is about 279.5626292406.

The spelling of 21849291 in words is "twenty-one million, eight hundred forty-nine thousand, two hundred ninety-one".