7778221441 has 2 divisors, whose sum is σ = 7778221442. Its totient is φ = 7778221440.

The previous prime is 7778221427. The next prime is 7778221469. The reversal of 7778221441 is 1441228777.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7624957041 + 153264400 = 87321^2 + 12380^2 .

It is an emirp because it is prime and its reverse (1441228777) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7778221441 - 2¹³ = 7778213249 is a prime.

It is not a weakly prime, because it can be changed into another prime (7778221411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3889110720 + 3889110721.

It is an arithmetic number, because the mean of its divisors is an integer number (3889110721).

Almost surely, 2^7778221441 is an apocalyptic number.

It is an amenable number.

7778221441 is a deficient number, since it is larger than the sum of its proper divisors (1).

7778221441 is an equidigital number, since it uses as much as digits as its factorization.

7778221441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 175616, while the sum is 43.

The square root of 7778221441 is about 88194.2256669902. The cubic root of 7778221441 is about 1981.3449897224.

The spelling of 7778221441 in words is "seven billion, seven hundred seventy-eight million, two hundred twenty-one thousand, four hundred forty-one".