2066991281 has 4 divisors (see below), whose sum is σ = 2067107364. Its totient is φ = 2066875200.

The previous prime is 2066991203. The next prime is 2066991293. The reversal of 2066991281 is 1821996602.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1213825600 + 853165681 = 34840^2 + 29209^2 .

It is a cyclic number.

It is not a de Polignac number, because 2066991281 - 2²² = 2062796977 is a prime.

It is a super-2 number, since 2×2066991281² = 8544905911460041922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2066991881) 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 3 ways as a sum of consecutive naturals, for example, 25100 + ... + 69021.

It is an arithmetic number, because the mean of its divisors is an integer number (516776841).

Almost surely, 2^2066991281 is an apocalyptic number.

It is an amenable number.

2066991281 is a deficient number, since it is larger than the sum of its proper divisors (116083).

2066991281 is an equidigital number, since it uses as much as digits as its factorization.

2066991281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116082.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 2066991281 is about 45464.1757980940. The cubic root of 2066991281 is about 1273.8341321978.

The spelling of 2066991281 in words is "two billion, sixty-six million, nine hundred ninety-one thousand, two hundred eighty-one".