2775172721 has 4 divisors (see below), whose sum is σ = 2775289344. Its totient is φ = 2775056100.

The previous prime is 2775172711. The next prime is 2775172723. The reversal of 2775172721 is 1272715772.

2775172721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2775172721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2775172723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8345 + ... + 74966.

It is an arithmetic number, because the mean of its divisors is an integer number (693822336).

Almost surely, 2^2775172721 is an apocalyptic number.

It is an amenable number.

2775172721 is a deficient number, since it is larger than the sum of its proper divisors (116623).

2775172721 is an equidigital number, since it uses as much as digits as its factorization.

2775172721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116622.

The product of its digits is 96040, while the sum is 41.

The square root of 2775172721 is about 52679.9081339366. The cubic root of 2775172721 is about 1405.2815333971.

The spelling of 2775172721 in words is "two billion, seven hundred seventy-five million, one hundred seventy-two thousand, seven hundred twenty-one".