7777778998 has 8 divisors (see below), whose sum is σ = 12727274760. Its totient is φ = 3535354080.

The previous prime is 7777778971. The next prime is 7777778999. The reversal of 7777778998 is 8998777777.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×7777778998² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7777778999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 176767683 + ... + 176767726.

It is an arithmetic number, because the mean of its divisors is an integer number (1590909345).

Almost surely, 2^7777778998 is an apocalyptic number.

7777778998 is a deficient number, since it is larger than the sum of its proper divisors (4949495762).

7777778998 is a wasteful number, since it uses less digits than its factorization.

7777778998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 353535422.

The product of its digits is 609892416, while the sum is 76.

The square root of 7777778998 is about 88191.7172868292. The cubic root of 7777778998 is about 1981.3074212006.

The spelling of 7777778998 in words is "seven billion, seven hundred seventy-seven million, seven hundred seventy-eight thousand, nine hundred ninety-eight".