7778398 has 4 divisors (see below), whose sum is σ = 11667600. Its totient is φ = 3889198.

The previous prime is 7778389. The next prime is 7778413. The reversal of 7778398 is 8938777.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8938777 = 73 ⋅122449.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1944598 + ... + 1944601.

It is an arithmetic number, because the mean of its divisors is an integer number (2916900).

Almost surely, 2^7778398 is an apocalyptic number.

7778398 is a deficient number, since it is larger than the sum of its proper divisors (3889202).

7778398 is a wasteful number, since it uses less digits than its factorization.

7778398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3889201.

The product of its digits is 592704, while the sum is 49.

The square root of 7778398 is about 2788.9779489985. The cubic root of 7778398 is about 198.1359981223.

The spelling of 7778398 in words is "seven million, seven hundred seventy-eight thousand, three hundred ninety-eight".