78319940 has 12 divisors (see below), whose sum is σ = 164471916. Its totient is φ = 31327968.

The previous prime is 78319933. The next prime is 78319949. The reversal of 78319940 is 4991387.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 58033924 + 20286016 = 7618^2 + 4504^2 .

It is a super-2 number, since 2×78319940² = 12268026003207200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78319949) 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, 1957979 + ... + 1958018.

It is an arithmetic number, because the mean of its divisors is an integer number (13705993).

Almost surely, 2^78319940 is an apocalyptic number.

It is an amenable number.

78319940 is an abundant number, since it is smaller than the sum of its proper divisors (86151976).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78319940 is a wasteful number, since it uses less digits than its factorization.

78319940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3916006 (or 3916004 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 78319940 is about 8849.8553660498. The cubic root of 78319940 is about 427.8492568974.

It can be divided in two parts, 7831 and 9940, that added together give a palindrome (17771).

The spelling of 78319940 in words is "seventy-eight million, three hundred nineteen thousand, nine hundred forty".