2191321026 has 96 divisors (see below), whose sum is σ = 5127595200. Its totient is φ = 700539840.

The previous prime is 2191321019. The next prime is 2191321031. The reversal of 2191321026 is 6201231912.

It is a super-3 number, since 3×2191321026³ (a number of 29 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2550585 + ... + 2551443.

It is an arithmetic number, because the mean of its divisors is an integer number (53412450).

Almost surely, 2^2191321026 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2191321026, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2563797600).

2191321026 is an abundant number, since it is smaller than the sum of its proper divisors (2936274174).

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

2191321026 is a wasteful number, since it uses less digits than its factorization.

2191321026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1086 (or 1074 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 2191321026 is about 46811.5479983305. The cubic root of 2191321026 is about 1298.8789202785.

Adding to 2191321026 its reverse (6201231912), we get a palindrome (8392552938).

The spelling of 2191321026 in words is "two billion, one hundred ninety-one million, three hundred twenty-one thousand, twenty-six".