2661840757 has 4 divisors (see below), whose sum is σ = 2662392096. Its totient is φ = 2661289420.

The previous prime is 2661840733. The next prime is 2661840767. The reversal of 2661840757 is 7570481662.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 7570481662 = 2 ⋅3785240831.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2661840757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2661840767) 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, 268363 + ... + 278104.

It is an arithmetic number, because the mean of its divisors is an integer number (665598024).

Almost surely, 2^2661840757 is an apocalyptic number.

It is an amenable number.

2661840757 is a deficient number, since it is larger than the sum of its proper divisors (551339).

2661840757 is an equidigital number, since it uses as much as digits as its factorization.

2661840757 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 551338.

The product of its (nonzero) digits is 564480, while the sum is 46.

The square root of 2661840757 is about 51593.0301203564. The cubic root of 2661840757 is about 1385.8855188501.

The spelling of 2661840757 in words is "two billion, six hundred sixty-one million, eight hundred forty thousand, seven hundred fifty-seven".