7766041721 has 2 divisors, whose sum is σ = 7766041722. Its totient is φ = 7766041720.

The previous prime is 7766041687. The next prime is 7766041837. The reversal of 7766041721 is 1271406677.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7730805625 + 35236096 = 87925^2 + 5936^2 .

It is a cyclic number.

It is not a de Polignac number, because 7766041721 - 2²² = 7761847417 is a prime.

It is a super-2 number, since 2×7766041721² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7766041421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3883020860 + 3883020861.

It is an arithmetic number, because the mean of its divisors is an integer number (3883020861).

Almost surely, 2^7766041721 is an apocalyptic number.

It is an amenable number.

7766041721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7766041721 is an equidigital number, since it uses as much as digits as its factorization.

7766041721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 98784, while the sum is 41.

The square root of 7766041721 is about 88125.1480622870. The cubic root of 7766041721 is about 1980.3102701375.

The spelling of 7766041721 in words is "seven billion, seven hundred sixty-six million, forty-one thousand, seven hundred twenty-one".