7721440997 has 2 divisors, whose sum is σ = 7721440998. Its totient is φ = 7721440996.

The previous prime is 7721440981. The next prime is 7721441003. The reversal of 7721440997 is 7990441277.

7721440997 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5618851681 + 2102589316 = 74959^2 + 45854^2 .

It is a cyclic number.

It is not a de Polignac number, because 7721440997 - 2⁴ = 7721440981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7721440957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3860720498 + 3860720499.

It is an arithmetic number, because the mean of its divisors is an integer number (3860720499).

Almost surely, 2^7721440997 is an apocalyptic number.

It is an amenable number.

7721440997 is a deficient number, since it is larger than the sum of its proper divisors (1).

7721440997 is an equidigital number, since it uses as much as digits as its factorization.

7721440997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 889056, while the sum is 50.

The square root of 7721440997 is about 87871.7303630696. The cubic root of 7721440997 is about 1976.5119861892.

The spelling of 7721440997 in words is "seven billion, seven hundred twenty-one million, four hundred forty thousand, nine hundred ninety-seven".