78991142 has 8 divisors (see below), whose sum is σ = 118524432. Its totient is φ = 39483000.

The previous prime is 78991141. The next prime is 78991153. The reversal of 78991142 is 24119987.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 78991142.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78991141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9092 + ... + 15512.

It is an arithmetic number, because the mean of its divisors is an integer number (14815554).

Almost surely, 2^78991142 is an apocalyptic number.

78991142 is a deficient number, since it is larger than the sum of its proper divisors (39533290).

78991142 is a wasteful number, since it uses less digits than its factorization.

78991142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12574.

The product of its digits is 36288, while the sum is 41.

The square root of 78991142 is about 8887.6961019153. The cubic root of 78991142 is about 429.0680048608.

The spelling of 78991142 in words is "seventy-eight million, nine hundred ninety-one thousand, one hundred forty-two".