7761720845 has 8 divisors (see below), whose sum is σ = 9314537976. Its totient is φ = 6209061376.

The previous prime is 7761720817. The next prime is 7761720853. The reversal of 7761720845 is 5480271677.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5924356 + 7755796489 = 2434^2 + 88067^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7761720845 - 2³⁰ = 6687979021 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7761720845.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171749 + ... + 212181.

It is an arithmetic number, because the mean of its divisors is an integer number (1164317247).

Almost surely, 2^7761720845 is an apocalyptic number.

It is an amenable number.

7761720845 is a deficient number, since it is larger than the sum of its proper divisors (1552817131).

7761720845 is a wasteful number, since it uses less digits than its factorization.

7761720845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78831.

The product of its (nonzero) digits is 658560, while the sum is 47.

The square root of 7761720845 is about 88100.6290840196. The cubic root of 7761720845 is about 1979.9429331748.

The spelling of 7761720845 in words is "seven billion, seven hundred sixty-one million, seven hundred twenty thousand, eight hundred forty-five".