26646306640 has 40 divisors (see below), whose sum is σ = 64088967240. Its totient is φ = 10290986496.

The previous prime is 26646306601. The next prime is 26646306689. The reversal of 26646306640 is 4660364662.

It can be written as a sum of positive squares in 4 ways, for example, as 333573696 + 26312732944 = 18264^2 + 162212^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5740419 + ... + 5745058.

It is an arithmetic number, because the mean of its divisors is an integer number (1602224181).

Almost surely, 2^26646306640 is an apocalyptic number.

26646306640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

26646306640 is an abundant number, since it is smaller than the sum of its proper divisors (37442660600).

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

26646306640 is a wasteful number, since it uses less digits than its factorization.

26646306640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11485519 (or 11485513 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 43.

The spelling of 26646306640 in words is "twenty-six billion, six hundred forty-six million, three hundred six thousand, six hundred forty".