78640444 has 12 divisors (see below), whose sum is σ = 137839968. Its totient is φ = 39257600.

The previous prime is 78640439. The next prime is 78640481. The reversal of 78640444 is 44404687.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12772 + ... + 17899.

It is an arithmetic number, because the mean of its divisors is an integer number (11486664).

Almost surely, 2^78640444 is an apocalyptic number.

It is an amenable number.

78640444 is a deficient number, since it is larger than the sum of its proper divisors (59199524).

78640444 is a wasteful number, since it uses less digits than its factorization.

78640444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31316 (or 31314 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 37.

The square root of 78640444 is about 8867.9447449790. The cubic root of 78640444 is about 428.4320832274.

The spelling of 78640444 in words is "seventy-eight million, six hundred forty thousand, four hundred forty-four".