7722381661 has 2 divisors, whose sum is σ = 7722381662. Its totient is φ = 7722381660.

The previous prime is 7722381659. The next prime is 7722381673. The reversal of 7722381661 is 1661832277.

7722381661 is digitally balanced in base 3, 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., 6970580100 + 751801561 = 83490^2 + 27419^2 .

It is a cyclic number.

It is not a de Polignac number, because 7722381661 - 2¹ = 7722381659 is a prime.

Together with 7722381659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7722385661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3861190830 + 3861190831.

It is an arithmetic number, because the mean of its divisors is an integer number (3861190831).

Almost surely, 2^7722381661 is an apocalyptic number.

It is an amenable number.

7722381661 is a deficient number, since it is larger than the sum of its proper divisors (1).

7722381661 is an equidigital number, since it uses as much as digits as its factorization.

7722381661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 169344, while the sum is 43.

The square root of 7722381661 is about 87877.0826837123. The cubic root of 7722381661 is about 1976.5922457408.

The spelling of 7722381661 in words is "seven billion, seven hundred twenty-two million, three hundred eighty-one thousand, six hundred sixty-one".