78939740 has 48 divisors (see below), whose sum is σ = 187094880. Its totient is φ = 27713280.

The previous prime is 78939697. The next prime is 78939761. The reversal of 78939740 is 4793987.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 194 + ... + 12566.

It is an arithmetic number, because the mean of its divisors is an integer number (3897810).

Almost surely, 2^78939740 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 78939740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93547440).

78939740 is an abundant number, since it is smaller than the sum of its proper divisors (108155140).

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

78939740 is a wasteful number, since it uses less digits than its factorization.

78939740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12422 (or 12420 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 47.

The square root of 78939740 is about 8884.8038807843. The cubic root of 78939740 is about 428.9749153543.

Subtracting from 78939740 its reverse (4793987), we obtain a triangular number (74145753 = T₁₂₁₇₇).

The spelling of 78939740 in words is "seventy-eight million, nine hundred thirty-nine thousand, seven hundred forty".