26991690880 has 256 divisors, whose sum is σ = 80702334720. Its totient is φ = 8386560000.

The previous prime is 26991690841. The next prime is 26991690899. The reversal of 26991690880 is 8809619962.

It is a super-2 number, since 2×26991690880² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20746230 + ... + 20747530.

It is an arithmetic number, because the mean of its divisors is an integer number (315243495).

Almost surely, 2^26991690880 is an apocalyptic number.

26991690880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 26991690880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40351167360).

26991690880 is an abundant number, since it is smaller than the sum of its proper divisors (53710643840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

26991690880 is a wasteful number, since it uses less digits than its factorization.

26991690880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1759 (or 1747 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 58.

The spelling of 26991690880 in words is "twenty-six billion, nine hundred ninety-one million, six hundred ninety thousand, eight hundred eighty".