2081721807 has 48 divisors (see below), whose sum is σ = 3368061216. Its totient is φ = 1228320000.

The previous prime is 2081721799. The next prime is 2081721857. The reversal of 2081721807 is 7081271802.

It is a happy number.

It is not a de Polignac number, because 2081721807 - 2³ = 2081721799 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2081721857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 608233 + ... + 611645.

It is an arithmetic number, because the mean of its divisors is an integer number (70167942).

Almost surely, 2^2081721807 is an apocalyptic number.

2081721807 is a deficient number, since it is larger than the sum of its proper divisors (1286339409).

2081721807 is a wasteful number, since it uses less digits than its factorization.

2081721807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3592 (or 3589 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 2081721807 is about 45625.8896570796. The cubic root of 2081721807 is about 1276.8529882864.

It can be divided in two parts, 20817 and 21807, that added together give a palindrome (42624).

The spelling of 2081721807 in words is "two billion, eighty-one million, seven hundred twenty-one thousand, eight hundred seven".