7778889998 has 32 divisors (see below), whose sum is σ = 12908160000. Its totient is φ = 3486244320.

The previous prime is 7778889983. The next prime is 7778890057. The reversal of 7778889998 is 8999888777.

It is a super-2 number, since 2×7778889998² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1438103 + ... + 1443501.

It is an arithmetic number, because the mean of its divisors is an integer number (403380000).

Almost surely, 2^7778889998 is an apocalyptic number.

7778889998 is a deficient number, since it is larger than the sum of its proper divisors (5129270002).

7778889998 is a wasteful number, since it uses less digits than its factorization.

7778889998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6320.

The product of its digits is 1024192512, while the sum is 80.

The square root of 7778889998 is about 88198.0158393600. The cubic root of 7778889998 is about 1981.4017552320.

The spelling of 7778889998 in words is "seven billion, seven hundred seventy-eight million, eight hundred eighty-nine thousand, nine hundred ninety-eight".