2806945721 has 2 divisors, whose sum is σ = 2806945722. Its totient is φ = 2806945720.

The previous prime is 2806945711. The next prime is 2806945723. The reversal of 2806945721 is 1275496082.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2799997225 + 6948496 = 52915^2 + 2636^2 .

It is a cyclic number.

It is not a de Polignac number, because 2806945721 - 2⁶ = 2806945657 is a prime.

Together with 2806945723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2806945723) 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 as a sum of consecutive naturals, namely, 1403472860 + 1403472861.

It is an arithmetic number, because the mean of its divisors is an integer number (1403472861).

Almost surely, 2^2806945721 is an apocalyptic number.

It is an amenable number.

2806945721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2806945721 is an equidigital number, since it uses as much as digits as its factorization.

2806945721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920, while the sum is 44.

The square root of 2806945721 is about 52980.6164648921. The cubic root of 2806945721 is about 1410.6242262297.

The spelling of 2806945721 in words is "two billion, eight hundred six million, nine hundred forty-five thousand, seven hundred twenty-one".