2081398591 has 4 divisors (see below), whose sum is σ = 2085638184. Its totient is φ = 2077159000.

The previous prime is 2081398577. The next prime is 2081398601. The reversal of 2081398591 is 1958931802.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2081398591 - 2⁷ = 2081398463 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2081398691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2119060 + ... + 2120041.

It is an arithmetic number, because the mean of its divisors is an integer number (521409546).

Almost surely, 2^2081398591 is an apocalyptic number.

2081398591 is a deficient number, since it is larger than the sum of its proper divisors (4239593).

2081398591 is an equidigital number, since it uses as much as digits as its factorization.

2081398591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4239592.

The product of its (nonzero) digits is 155520, while the sum is 46.

The square root of 2081398591 is about 45622.3474954983. The cubic root of 2081398591 is about 1276.7869018582.

The spelling of 2081398591 in words is "two billion, eighty-one million, three hundred ninety-eight thousand, five hundred ninety-one".