20718849 has 4 divisors (see below), whose sum is σ = 27625136. Its totient is φ = 13812564.

The previous prime is 20718839. The next prime is 20718851. The reversal of 20718849 is 94881702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20718849 - 2⁹ = 20718337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20718809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3453139 + ... + 3453144.

It is an arithmetic number, because the mean of its divisors is an integer number (6906284).

Almost surely, 2^20718849 is an apocalyptic number.

It is an amenable number.

20718849 is a deficient number, since it is larger than the sum of its proper divisors (6906287).

20718849 is an equidigital number, since it uses as much as digits as its factorization.

20718849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6906286.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 20718849 is about 4551.7962388490. The cubic root of 20718849 is about 274.6556527446.

The spelling of 20718849 in words is "twenty million, seven hundred eighteen thousand, eight hundred forty-nine".