21086849 has 8 divisors (see below), whose sum is σ = 24132288. Its totient is φ = 18049680.

The previous prime is 21086839. The next prime is 21086861. The reversal of 21086849 is 94868012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21086849 - 2²⁰ = 20038273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21086839) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5039 + ... + 8219.

It is an arithmetic number, because the mean of its divisors is an integer number (3016536).

Almost surely, 2^21086849 is an apocalyptic number.

It is an amenable number.

21086849 is a deficient number, since it is larger than the sum of its proper divisors (3045439).

21086849 is an equidigital number, since it uses as much as digits as its factorization.

21086849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4135.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 21086849 is about 4592.0419205404. The cubic root of 21086849 is about 276.2722275543.

The spelling of 21086849 in words is "twenty-one million, eighty-six thousand, eight hundred forty-nine".