7878385961 has 2 divisors, whose sum is σ = 7878385962. Its totient is φ = 7878385960.

The previous prime is 7878385901. The next prime is 7878385969. The reversal of 7878385961 is 1695838787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5322577936 + 2555808025 = 72956^2 + 50555^2 .

It is a cyclic number.

It is not a de Polignac number, because 7878385961 - 2¹⁰ = 7878384937 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 7878385894 and 7878385903.

It is not a weakly prime, because it can be changed into another prime (7878385969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3939192980 + 3939192981.

It is an arithmetic number, because the mean of its divisors is an integer number (3939192981).

Almost surely, 2^7878385961 is an apocalyptic number.

It is an amenable number.

7878385961 is a deficient number, since it is larger than the sum of its proper divisors (1).

7878385961 is an equidigital number, since it uses as much as digits as its factorization.

7878385961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20321280, while the sum is 62.

The square root of 7878385961 is about 88760.2724252241. The cubic root of 7878385961 is about 1989.8137045202.

The spelling of 7878385961 in words is "seven billion, eight hundred seventy-eight million, three hundred eighty-five thousand, nine hundred sixty-one".