7782799991 has 2 divisors, whose sum is σ = 7782799992. Its totient is φ = 7782799990.

The previous prime is 7782799979. The next prime is 7782800009. The reversal of 7782799991 is 1999972877.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 7782799991 - 2¹⁴ = 7782783607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7782799951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3891399995 + 3891399996.

It is an arithmetic number, because the mean of its divisors is an integer number (3891399996).

Almost surely, 2^7782799991 is an apocalyptic number.

7782799991 is a deficient number, since it is larger than the sum of its proper divisors (1).

7782799991 is an equidigital number, since it uses as much as digits as its factorization.

7782799991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36006768, while the sum is 68.

The square root of 7782799991 is about 88220.1790465197. The cubic root of 7782799991 is about 1981.7336778810.

The spelling of 7782799991 in words is "seven billion, seven hundred eighty-two million, seven hundred ninety-nine thousand, nine hundred ninety-one".