2666720289 has 4 divisors (see below), whose sum is σ = 3555627056. Its totient is φ = 1777813524.

The previous prime is 2666720269. The next prime is 2666720299. The reversal of 2666720289 is 9820276662.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2666720289 - 2⁸ = 2666720033 is a prime.

It is a super-2 number, since 2×2666720289² = 14222794199528487042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2666720269) 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, 444453379 + ... + 444453384.

It is an arithmetic number, because the mean of its divisors is an integer number (888906764).

Almost surely, 2^2666720289 is an apocalyptic number.

It is an amenable number.

2666720289 is a deficient number, since it is larger than the sum of its proper divisors (888906767).

2666720289 is an equidigital number, since it uses as much as digits as its factorization.

2666720289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 888906766.

The product of its (nonzero) digits is 870912, while the sum is 48.

The square root of 2666720289 is about 51640.2971428322. The cubic root of 2666720289 is about 1386.7318435513.

The spelling of 2666720289 in words is "two billion, six hundred sixty-six million, seven hundred twenty thousand, two hundred eighty-nine".