26561635620 has 96 divisors (see below), whose sum is σ = 80192343168. Its totient is φ = 6530184192.

The previous prime is 26561635603. The next prime is 26561635621. The reversal of 26561635620 is 2653616562.

It is not an unprimeable number, because it can be changed into a prime (26561635621) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 624472 + ... + 665648.

It is an arithmetic number, because the mean of its divisors is an integer number (835336908).

Almost surely, 2^26561635620 is an apocalyptic number.

26561635620 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 26561635620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40096171584).

26561635620 is an abundant number, since it is smaller than the sum of its proper divisors (53630707548).

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

26561635620 is a wasteful number, since it uses less digits than its factorization.

26561635620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42029 (or 42027 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 42.

The spelling of 26561635620 in words is "twenty-six billion, five hundred sixty-one million, six hundred thirty-five thousand, six hundred twenty".