20892681217 has 4 divisors (see below), whose sum is σ = 20895143940. Its totient is φ = 20890218496.

The previous prime is 20892681211. The next prime is 20892681239. The reversal of 20892681217 is 71218629802.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15346006641 + 5546674576 = 123879^2 + 74476^2 .

It is a cyclic number.

It is not a de Polignac number, because 20892681217 - 2³ = 20892681209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20892681211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1218592 + ... + 1235617.

It is an arithmetic number, because the mean of its divisors is an integer number (5223785985).

Almost surely, 2^20892681217 is an apocalyptic number.

It is an amenable number.

20892681217 is a deficient number, since it is larger than the sum of its proper divisors (2462723).

20892681217 is an equidigital number, since it uses as much as digits as its factorization.

20892681217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2462722.

The product of its (nonzero) digits is 193536, while the sum is 46.

The spelling of 20892681217 in words is "twenty billion, eight hundred ninety-two million, six hundred eighty-one thousand, two hundred seventeen".