2981386721 has 2 divisors, whose sum is σ = 2981386722. Its totient is φ = 2981386720.

The previous prime is 2981386711. The next prime is 2981386741. The reversal of 2981386721 is 1276831892.

It is a happy number.

2981386721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2957728225 + 23658496 = 54385^2 + 4864^2 .

It is a cyclic number.

It is not a de Polignac number, because 2981386721 - 2⁶ = 2981386657 is a prime.

It is not a weakly prime, because it can be changed into another prime (2981386711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1490693360 + 1490693361.

It is an arithmetic number, because the mean of its divisors is an integer number (1490693361).

Almost surely, 2^2981386721 is an apocalyptic number.

It is an amenable number.

2981386721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2981386721 is an equidigital number, since it uses as much as digits as its factorization.

2981386721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 47.

The square root of 2981386721 is about 54602.0761601608. The cubic root of 2981386721 is about 1439.2606030778.

The spelling of 2981386721 in words is "two billion, nine hundred eighty-one million, three hundred eighty-six thousand, seven hundred twenty-one".