78440667 has 8 divisors (see below), whose sum is σ = 107138640. Its totient is φ = 51018240.

The previous prime is 78440657. The next prime is 78440671. The reversal of 78440667 is 76604487.

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

It is not a de Polignac number, because 78440667 - 2¹⁰ = 78439643 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (78440647) 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, 318742 + ... + 318987.

It is an arithmetic number, because the mean of its divisors is an integer number (13392330).

Almost surely, 2^78440667 is an apocalyptic number.

78440667 is a deficient number, since it is larger than the sum of its proper divisors (28697973).

78440667 is a wasteful number, since it uses less digits than its factorization.

78440667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637773.

The product of its (nonzero) digits is 225792, while the sum is 42.

The square root of 78440667 is about 8856.6735854947. The cubic root of 78440667 is about 428.0689814428.

The spelling of 78440667 in words is "seventy-eight million, four hundred forty thousand, six hundred sixty-seven".