20838644847 has 16 divisors (see below), whose sum is σ = 30902582880. Its totient is φ = 13878697536.

The previous prime is 20838644843. The next prime is 20838644891. The reversal of 20838644847 is 74844683802.

It is a happy number.

20838644847 is a `hidden beast` number, since 2 + 0 + 83 + 86 + 4 + 484 + 7 = 666.

It is not a de Polignac number, because 20838644847 - 2² = 20838644843 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20838644793 and 20838644802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20838644843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 353598 + ... + 408299.

It is an arithmetic number, because the mean of its divisors is an integer number (1931411430).

Almost surely, 2^20838644847 is an apocalyptic number.

20838644847 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

20838644847 is a deficient number, since it is larger than the sum of its proper divisors (10063938033).

20838644847 is a wasteful number, since it uses less digits than its factorization.

20838644847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 762919 (or 762913 counting only the distinct ones).

The product of its (nonzero) digits is 8257536, while the sum is 54.

The spelling of 20838644847 in words is "twenty billion, eight hundred thirty-eight million, six hundred forty-four thousand, eight hundred forty-seven".