26591991552 has 432 divisors, whose sum is σ = 92138941440. Its totient is φ = 7491833856.

The previous prime is 26591991551. The next prime is 26591991589. The reversal of 26591991552 is 25519919562.

26591991552 is a `hidden beast` number, since 26 + 59 + 19 + 9 + 1 + 552 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26591991551) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 34400638 + ... + 34401410.

Almost surely, 2^26591991552 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 26591991552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46069470720).

26591991552 is an abundant number, since it is smaller than the sum of its proper divisors (65546949888).

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

26591991552 is an frugal number, since it uses more digits than its factorization.

26591991552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 890 (or 864 counting only the distinct ones).

The product of its digits is 2187000, while the sum is 54.

The spelling of 26591991552 in words is "twenty-six billion, five hundred ninety-one million, nine hundred ninety-one thousand, five hundred fifty-two".