26257824640 has 128 divisors (see below), whose sum is σ = 67880592000. Its totient is φ = 9674784768.

The previous prime is 26257824599. The next prime is 26257824643. The reversal of 26257824640 is 4642875262.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×26257824640² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26257824643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 485686 + ... + 537034.

It is an arithmetic number, because the mean of its divisors is an integer number (530317125).

Almost surely, 2^26257824640 is an apocalyptic number.

26257824640 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 26257824640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33940296000).

26257824640 is an abundant number, since it is smaller than the sum of its proper divisors (41622767360).

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

26257824640 is a wasteful number, since it uses less digits than its factorization.

26257824640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51432 (or 51420 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 46.

The spelling of 26257824640 in words is "twenty-six billion, two hundred fifty-seven million, eight hundred twenty-four thousand, six hundred forty".