78446609 has 4 divisors (see below), whose sum is σ = 78638820. Its totient is φ = 78254400.

The previous prime is 78446593. The next prime is 78446633. The reversal of 78446609 is 90664487.

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

It can be written as a sum of positive squares in 2 ways, for example, as 30283009 + 48163600 = 5503^2 + 6940^2 .

It is a cyclic number.

It is not a de Polignac number, because 78446609 - 2⁴ = 78446593 is a prime.

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 78446609.

It is not an unprimeable number, because it can be changed into a prime (78446509) 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, 95492 + ... + 96309.

It is an arithmetic number, because the mean of its divisors is an integer number (19659705).

Almost surely, 2^78446609 is an apocalyptic number.

It is an amenable number.

78446609 is a deficient number, since it is larger than the sum of its proper divisors (192211).

78446609 is a wasteful number, since it uses less digits than its factorization.

78446609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192210.

The product of its (nonzero) digits is 290304, while the sum is 44.

The square root of 78446609 is about 8857.0090323991. The cubic root of 78446609 is about 428.0797901290.

The spelling of 78446609 in words is "seventy-eight million, four hundred forty-six thousand, six hundred nine".