26921784869 has 6 divisors (see below), whose sum is σ = 31317178374. Its totient is φ = 23075815560.

The previous prime is 26921784839. The next prime is 26921784871. The reversal of 26921784869 is 96848712962.

It can be written as a sum of positive squares in only one way, i.e., 26430630625 + 491154244 = 162575^2 + 22162^2 .

It is a de Polignac number, because none of the positive numbers 2^k-26921784869 is a prime.

It is a super-2 number, since 2×26921784869² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26921784839) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 274712042 + ... + 274712139.

It is an arithmetic number, because the mean of its divisors is an integer number (5219529729).

Almost surely, 2^26921784869 is an apocalyptic number.

It is an amenable number.

26921784869 is a deficient number, since it is larger than the sum of its proper divisors (4395393505).

26921784869 is an equidigital number, since it uses as much as digits as its factorization.

26921784869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549424195 (or 549424188 counting only the distinct ones).

The product of its digits is 20901888, while the sum is 62.

The spelling of 26921784869 in words is "twenty-six billion, nine hundred twenty-one million, seven hundred eighty-four thousand, eight hundred sixty-nine".