78439870 has 16 divisors (see below), whose sum is σ = 149497488. Its totient is φ = 29530240.

The previous prime is 78439859. The next prime is 78439871. The reversal of 78439870 is 7893487.

It is a self number, because there is not a number n which added to its sum of digits gives 78439870.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78439871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 230536 + ... + 230875.

It is an arithmetic number, because the mean of its divisors is an integer number (9343593).

Almost surely, 2^78439870 is an apocalyptic number.

78439870 is a deficient number, since it is larger than the sum of its proper divisors (71057618).

78439870 is a wasteful number, since it uses less digits than its factorization.

78439870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461435.

The product of its (nonzero) digits is 338688, while the sum is 46.

The square root of 78439870 is about 8856.6285910610. The cubic root of 78439870 is about 428.0675316330.

The spelling of 78439870 in words is "seventy-eight million, four hundred thirty-nine thousand, eight hundred seventy".