20806455849 has 4 divisors (see below), whose sum is σ = 27741941136. Its totient is φ = 13870970564.

The previous prime is 20806455827. The next prime is 20806455869. The reversal of 20806455849 is 94855460802.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 20806455849 - 2²⁵ = 20772901417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20806455869) 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, 3467742639 + ... + 3467742644.

It is an arithmetic number, because the mean of its divisors is an integer number (6935485284).

Almost surely, 2^20806455849 is an apocalyptic number.

It is an amenable number.

20806455849 is a deficient number, since it is larger than the sum of its proper divisors (6935485287).

20806455849 is an equidigital number, since it uses as much as digits as its factorization.

20806455849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6935485286.

The product of its (nonzero) digits is 2764800, while the sum is 51.

The spelling of 20806455849 in words is "twenty billion, eight hundred six million, four hundred fifty-five thousand, eight hundred forty-nine".