78909780 has 96 divisors (see below), whose sum is σ = 232501248. Its totient is φ = 19958400.

The previous prime is 78909769. The next prime is 78909781. The reversal of 78909780 is 8790987.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78909781) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 291045 + ... + 291315.

It is an arithmetic number, because the mean of its divisors is an integer number (2421888).

Almost surely, 2^78909780 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 78909780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116250624).

78909780 is an abundant number, since it is smaller than the sum of its proper divisors (153591468).

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

78909780 is a wasteful number, since it uses less digits than its factorization.

78909780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517 (or 515 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 48.

The square root of 78909780 is about 8883.1176959444. The cubic root of 78909780 is about 428.9206388698.

The spelling of 78909780 in words is "seventy-eight million, nine hundred nine thousand, seven hundred eighty".