78309040 has 20 divisors (see below), whose sum is σ = 182068704. Its totient is φ = 31323584.

The previous prime is 78308999. The next prime is 78309059. The reversal of 78309040 is 4090387.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×78309040² = 12264611491443200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78308993 and 78309011.

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 3 ways as a sum of consecutive naturals, for example, 489352 + ... + 489511.

Almost surely, 2^78309040 is an apocalyptic number.

It is an amenable number.

78309040 is an abundant number, since it is smaller than the sum of its proper divisors (103759664).

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

78309040 is a wasteful number, since it uses less digits than its factorization.

78309040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 978876 (or 978870 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 78309040 is about 8849.2395153482. The cubic root of 78309040 is about 427.8294076599.

The spelling of 78309040 in words is "seventy-eight million, three hundred nine thousand, forty".