78939770 has 64 divisors (see below), whose sum is σ = 176117760. Its totient is φ = 24807168.

The previous prime is 78939761. The next prime is 78939779. The reversal of 78939770 is 7793987.

It is an interprime number because it is at equal distance from previous prime (78939761) and next prime (78939779).

It is not an unprimeable number, because it can be changed into a prime (78939779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 202736 + ... + 203124.

It is an arithmetic number, because the mean of its divisors is an integer number (2751840).

Almost surely, 2^78939770 is an apocalyptic number.

78939770 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

78939770 is an abundant number, since it is smaller than the sum of its proper divisors (97177990).

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

78939770 is a wasteful number, since it uses less digits than its factorization.

78939770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639.

The product of its (nonzero) digits is 666792, while the sum is 50.

The square root of 78939770 is about 8884.8055690600. The cubic root of 78939770 is about 428.9749696964.

The spelling of 78939770 in words is "seventy-eight million, nine hundred thirty-nine thousand, seven hundred seventy".