20971893955 has 4 divisors (see below), whose sum is σ = 25166272752. Its totient is φ = 16777515160.

The previous prime is 20971893941. The next prime is 20971894037. The reversal of 20971893955 is 55939817902.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20971893955 - 2¹¹ = 20971891907 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20971893955.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2097189391 + ... + 2097189400.

It is an arithmetic number, because the mean of its divisors is an integer number (6291568188).

Almost surely, 2^20971893955 is an apocalyptic number.

20971893955 is a deficient number, since it is larger than the sum of its proper divisors (4194378797).

20971893955 is an equidigital number, since it uses as much as digits as its factorization.

20971893955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4194378796.

The product of its (nonzero) digits is 6123600, while the sum is 58.

The spelling of 20971893955 in words is "twenty billion, nine hundred seventy-one million, eight hundred ninety-three thousand, nine hundred fifty-five".