2661267761 has 4 divisors (see below), whose sum is σ = 2693331312. Its totient is φ = 2629204212.

The previous prime is 2661267743. The next prime is 2661267767. The reversal of 2661267761 is 1677621662.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2661267761 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2661267767) 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, 16031651 + ... + 16031816.

It is an arithmetic number, because the mean of its divisors is an integer number (673332828).

Almost surely, 2^2661267761 is an apocalyptic number.

It is an amenable number.

2661267761 is a deficient number, since it is larger than the sum of its proper divisors (32063551).

2661267761 is an equidigital number, since it uses as much as digits as its factorization.

2661267761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32063550.

The product of its digits is 254016, while the sum is 44.

The square root of 2661267761 is about 51587.4767845841. The cubic root of 2661267761 is about 1385.7860683922.

The spelling of 2661267761 in words is "two billion, six hundred sixty-one million, two hundred sixty-seven thousand, seven hundred sixty-one".