7778880 has 168 divisors, whose sum is σ = 27855672. Its totient is φ = 1990656.

The previous prime is 7778839. The next prime is 7778891. The reversal of 7778880 is 888777.

It can be written as a sum of positive squares in 4 ways, for example, as 2359296 + 5419584 = 1536^2 + 2328^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 106524 + ... + 106596.

Almost surely, 2^7778880 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7778880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13927836).

7778880 is an abundant number, since it is smaller than the sum of its proper divisors (20076792).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7778880 is a wasteful number, since it uses less digits than its factorization.

7778880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 175616, while the sum is 45.

The square root of 7778880 is about 2789.0643592431. The cubic root of 7778880 is about 198.1400906351.

The spelling of 7778880 in words is "seven million, seven hundred seventy-eight thousand, eight hundred eighty".