78487131 has 4 divisors (see below), whose sum is σ = 104649512. Its totient is φ = 52324752.

The previous prime is 78487127. The next prime is 78487139. The reversal of 78487131 is 13178487.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 78487131 - 2² = 78487127 is a prime.

It is a super-2 number, since 2×78487131² = 12320459465222322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78487131.

It is not an unprimeable number, because it can be changed into a prime (78487139) 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, 13081186 + ... + 13081191.

It is an arithmetic number, because the mean of its divisors is an integer number (26162378).

Almost surely, 2^78487131 is an apocalyptic number.

78487131 is a deficient number, since it is larger than the sum of its proper divisors (26162381).

78487131 is a wasteful number, since it uses less digits than its factorization.

78487131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26162380.

The product of its digits is 37632, while the sum is 39.

The square root of 78487131 is about 8859.2963038833. The cubic root of 78487131 is about 428.1534863813.

The spelling of 78487131 in words is "seventy-eight million, four hundred eighty-seven thousand, one hundred thirty-one".