7978418813 has 2 divisors, whose sum is σ = 7978418814. Its totient is φ = 7978418812.

The previous prime is 7978418771. The next prime is 7978418837. The reversal of 7978418813 is 3188148797.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6707282404 + 1271136409 = 81898^2 + 35653^2 .

It is a cyclic number.

It is not a de Polignac number, because 7978418813 - 2⁸ = 7978418557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7978418863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3989209406 + 3989209407.

It is an arithmetic number, because the mean of its divisors is an integer number (3989209407).

Almost surely, 2^7978418813 is an apocalyptic number.

It is an amenable number.

7978418813 is a deficient number, since it is larger than the sum of its proper divisors (1).

7978418813 is an equidigital number, since it uses as much as digits as its factorization.

7978418813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2709504, while the sum is 56.

The square root of 7978418813 is about 89321.9951243813. The cubic root of 7978418813 is about 1998.1999481427.

The spelling of 7978418813 in words is "seven billion, nine hundred seventy-eight million, four hundred eighteen thousand, eight hundred thirteen".