78287986 has 24 divisors (see below), whose sum is σ = 136966896. Its totient is φ = 33463080.

The previous prime is 78287981. The next prime is 78288013. The reversal of 78287986 is 68978287.

It is a super-2 number, since 2×78287986² = 12258017503872392, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78287981) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 47305 + ... + 48931.

It is an arithmetic number, because the mean of its divisors is an integer number (5706954).

Almost surely, 2^78287986 is an apocalyptic number.

78287986 is a deficient number, since it is larger than the sum of its proper divisors (58678910).

78287986 is a wasteful number, since it uses less digits than its factorization.

78287986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2134 (or 2127 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 55.

The square root of 78287986 is about 8848.0498416318. The cubic root of 78287986 is about 427.7910624586.

It can be divided in two parts, 7828798 and 6, that added together give a square (7828804 = 2798²).

The spelling of 78287986 in words is "seventy-eight million, two hundred eighty-seven thousand, nine hundred eighty-six".