7778420249 has 2 divisors, whose sum is σ = 7778420250. Its totient is φ = 7778420248.

The previous prime is 7778420219. The next prime is 7778420257. The reversal of 7778420249 is 9420248777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4006003849 + 3772416400 = 63293^2 + 61420^2 .

It is a cyclic number.

It is not a de Polignac number, because 7778420249 - 2¹² = 7778416153 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 7778420197 and 7778420206.

It is not a weakly prime, because it can be changed into another prime (7778420219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3889210124 + 3889210125.

It is an arithmetic number, because the mean of its divisors is an integer number (3889210125).

Almost surely, 2^7778420249 is an apocalyptic number.

It is an amenable number.

7778420249 is a deficient number, since it is larger than the sum of its proper divisors (1).

7778420249 is an equidigital number, since it uses as much as digits as its factorization.

7778420249 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1580544, while the sum is 50.

The square root of 7778420249 is about 88195.3527630566. The cubic root of 7778420249 is about 1981.3618703543.

The spelling of 7778420249 in words is "seven billion, seven hundred seventy-eight million, four hundred twenty thousand, two hundred forty-nine".