7766423617721 has 2 divisors, whose sum is σ = 7766423617722. Its totient is φ = 7766423617720.

The previous prime is 7766423617663. The next prime is 7766423617769. The reversal of 7766423617721 is 1277163246677.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7187819982121 + 578603635600 = 2681011^2 + 760660^2 .

It is a cyclic number.

It is not a de Polignac number, because 7766423617721 - 2¹⁴ = 7766423601337 is a prime.

It is not a weakly prime, because it can be changed into another prime (7766423617021) 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, 3883211808860 + 3883211808861.

It is an arithmetic number, because the mean of its divisors is an integer number (3883211808861).

Almost surely, 2^{7766423617721} is an apocalyptic number.

It is an amenable number.

7766423617721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7766423617721 is an equidigital number, since it uses as much as digits as its factorization.

7766423617721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24893568, while the sum is 59.

The spelling of 7766423617721 in words is "seven trillion, seven hundred sixty-six billion, four hundred twenty-three million, six hundred seventeen thousand, seven hundred twenty-one".