2678072721 has 4 divisors (see below), whose sum is σ = 3570763632. Its totient is φ = 1785381812.

The previous prime is 2678072699. The next prime is 2678072729. The reversal of 2678072721 is 1272708762.

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-2678072721 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2678072729) 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, 446345451 + ... + 446345456.

It is an arithmetic number, because the mean of its divisors is an integer number (892690908).

Almost surely, 2^2678072721 is an apocalyptic number.

It is an amenable number.

2678072721 is a deficient number, since it is larger than the sum of its proper divisors (892690911).

2678072721 is an equidigital number, since it uses as much as digits as its factorization.

2678072721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 892690910.

The product of its (nonzero) digits is 131712, while the sum is 42.

The square root of 2678072721 is about 51750.0987535290. The cubic root of 2678072721 is about 1388.6968655674.

The spelling of 2678072721 in words is "two billion, six hundred seventy-eight million, seventy-two thousand, seven hundred twenty-one".