78991143 has 16 divisors (see below), whose sum is σ = 131310336. Its totient is φ = 41034240.

The previous prime is 78991141. The next prime is 78991153. The reversal of 78991143 is 34119987.

It is a happy number.

It is not a de Polignac number, because 78991143 - 2¹ = 78991141 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78991095 and 78991104.

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 15 ways as a sum of consecutive naturals, for example, 170746 + ... + 171207.

It is an arithmetic number, because the mean of its divisors is an integer number (8206896).

Almost surely, 2^78991143 is an apocalyptic number.

78991143 is a deficient number, since it is larger than the sum of its proper divisors (52319193).

78991143 is a wasteful number, since it uses less digits than its factorization.

78991143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341974.

The product of its digits is 54432, while the sum is 42.

The square root of 78991143 is about 8887.6961581728. The cubic root of 78991143 is about 429.0680066714.

The spelling of 78991143 in words is "seventy-eight million, nine hundred ninety-one thousand, one hundred forty-three".