78866009 has 8 divisors (see below), whose sum is σ = 83589408. Its totient is φ = 74152000.

The previous prime is 78865991. The next prime is 78866023. The reversal of 78866009 is 90066887.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78866009 - 2¹⁶ = 78800473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78866069) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22634 + ... + 25884.

It is an arithmetic number, because the mean of its divisors is an integer number (10448676).

Almost surely, 2^78866009 is an apocalyptic number.

It is an amenable number.

78866009 is a deficient number, since it is larger than the sum of its proper divisors (4723399).

78866009 is a wasteful number, since it uses less digits than its factorization.

78866009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4695.

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 78866009 is about 8880.6536358536. The cubic root of 78866009 is about 428.8413172374.

The spelling of 78866009 in words is "seventy-eight million, eight hundred sixty-six thousand, nine".