26566819840 has 128 divisors (see below), whose sum is σ = 69560421840. Its totient is φ = 9660006400.

The previous prime is 26566819823. The next prime is 26566819843. The reversal of 26566819840 is 4891866562.

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

It is a super-2 number, since 2×26566819840² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26566819843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1794870 + ... + 1809610.

Almost surely, 2^26566819840 is an apocalyptic number.

26566819840 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 26566819840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34780210920).

26566819840 is an abundant number, since it is smaller than the sum of its proper divisors (42993602000).

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

26566819840 is an equidigital number, since it uses as much as digits as its factorization.

26566819840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14787 (or 14759 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 55.

The spelling of 26566819840 in words is "twenty-six billion, five hundred sixty-six million, eight hundred nineteen thousand, eight hundred forty".