78047780 has 24 divisors (see below), whose sum is σ = 164625720. Its totient is φ = 31080960.

The previous prime is 78047779. The next prime is 78047791. The reversal of 78047780 is 8774087.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 41783296 + 36264484 = 6464^2 + 6022^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3941 + ... + 13100.

It is an arithmetic number, because the mean of its divisors is an integer number (6859405).

Almost surely, 2^78047780 is an apocalyptic number.

It is an amenable number.

78047780 is an abundant number, since it is smaller than the sum of its proper divisors (86577940).

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

78047780 is a wasteful number, since it uses less digits than its factorization.

78047780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17279 (or 17277 counting only the distinct ones).

The product of its (nonzero) digits is 87808, while the sum is 41.

The square root of 78047780 is about 8834.4654620413. The cubic root of 78047780 is about 427.3530929397.

The spelling of 78047780 in words is "seventy-eight million, forty-seven thousand, seven hundred eighty".