26661229780 has 48 divisors (see below), whose sum is σ = 59076360000. Its totient is φ = 10079030016.

The previous prime is 26661229753. The next prime is 26661229781. The reversal of 26661229780 is 8792216662.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26661229781) 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, 75496 + ... + 242944.

It is an arithmetic number, because the mean of its divisors is an integer number (1230757500).

Almost surely, 2^26661229780 is an apocalyptic number.

26661229780 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 26661229780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29538180000).

26661229780 is an abundant number, since it is smaller than the sum of its proper divisors (32415130220).

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

26661229780 is a wasteful number, since it uses less digits than its factorization.

26661229780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167896 (or 167894 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 49.

The spelling of 26661229780 in words is "twenty-six billion, six hundred sixty-one million, two hundred twenty-nine thousand, seven hundred eighty".