78747978 has 32 divisors (see below), whose sum is σ = 167239296. Its totient is φ = 24634368.

The previous prime is 78747973. The next prime is 78747997. The reversal of 78747978 is 87974787.

It is not an unprimeable number, because it can be changed into a prime (78747973) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43275 + ... + 45057.

It is an arithmetic number, because the mean of its divisors is an integer number (5226228).

Almost surely, 2^78747978 is an apocalyptic number.

78747978 is an abundant number, since it is smaller than the sum of its proper divisors (88491318).

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

78747978 is a wasteful number, since it uses less digits than its factorization.

78747978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2238.

The product of its digits is 5531904, while the sum is 57.

The square root of 78747978 is about 8874.0057471246. The cubic root of 78747978 is about 428.6272755477.

The spelling of 78747978 in words is "seventy-eight million, seven hundred forty-seven thousand, nine hundred seventy-eight".