78977986 has 16 divisors (see below), whose sum is σ = 121601088. Its totient is φ = 38458000.

The previous prime is 78977957. The next prime is 78978007. The reversal of 78977986 is 68977987.

It is a super-3 number, since 3×78977986³ (a number of 25 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8436 + ... + 15136.

It is an arithmetic number, because the mean of its divisors is an integer number (7600068).

Almost surely, 2^78977986 is an apocalyptic number.

78977986 is a deficient number, since it is larger than the sum of its proper divisors (42623102).

78977986 is a wasteful number, since it uses less digits than its factorization.

78977986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6857.

The product of its digits is 10668672, while the sum is 61.

The square root of 78977986 is about 8886.9559467795. The cubic root of 78977986 is about 429.0441830670.

Subtracting from 78977986 its reverse (68977987), we obtain a palindrome (9999999).

The spelling of 78977986 in words is "seventy-eight million, nine hundred seventy-seven thousand, nine hundred eighty-six".