2660738681 has 4 divisors (see below), whose sum is σ = 2663603700. Its totient is φ = 2657873664.

The previous prime is 2660738677. The next prime is 2660738713. The reversal of 2660738681 is 1868370662.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1460462656 + 1200276025 = 38216^2 + 34645^2 .

It is a cyclic number.

It is not a de Polignac number, because 2660738681 - 2² = 2660738677 is a prime.

It is a super-2 number, since 2×2660738681² = 14159060657139239522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2660738621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1431116 + ... + 1432973.

It is an arithmetic number, because the mean of its divisors is an integer number (665900925).

Almost surely, 2^2660738681 is an apocalyptic number.

It is an amenable number.

2660738681 is a deficient number, since it is larger than the sum of its proper divisors (2865019).

2660738681 is an equidigital number, since it uses as much as digits as its factorization.

2660738681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2865018.

The product of its (nonzero) digits is 580608, while the sum is 47.

The square root of 2660738681 is about 51582.3485409495. The cubic root of 2660738681 is about 1385.6942274162.

The spelling of 2660738681 in words is "two billion, six hundred sixty million, seven hundred thirty-eight thousand, six hundred eighty-one".