26791221660 has 192 divisors, whose sum is σ = 87480056832. Its totient is φ = 5999837184.

The previous prime is 26791221623. The next prime is 26791221679. The reversal of 26791221660 is 6612219762.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5428554 + ... + 5433486.

It is an arithmetic number, because the mean of its divisors is an integer number (455625296).

Almost surely, 2^26791221660 is an apocalyptic number.

26791221660 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 26791221660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43740028416).

26791221660 is an abundant number, since it is smaller than the sum of its proper divisors (60688835172).

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

26791221660 is a wasteful number, since it uses less digits than its factorization.

26791221660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5212 (or 5210 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 42.

The spelling of 26791221660 in words is "twenty-six billion, seven hundred ninety-one million, two hundred twenty-one thousand, six hundred sixty".