78391004 has 12 divisors (see below), whose sum is σ = 138265344. Its totient is φ = 38886624.

The previous prime is 78390997. The next prime is 78391007. The reversal of 78391004 is 40019387.

It is a super-2 number, since 2×78391004² = 12290299016256032, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78391007) by changing a digit.

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, 76649 + ... + 77664.

It is an arithmetic number, because the mean of its divisors is an integer number (11522112).

Almost surely, 2^78391004 is an apocalyptic number.

It is an amenable number.

78391004 is a deficient number, since it is larger than the sum of its proper divisors (59874340).

78391004 is a wasteful number, since it uses less digits than its factorization.

78391004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154444 (or 154442 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 78391004 is about 8853.8694365797. The cubic root of 78391004 is about 427.9786215193.

The spelling of 78391004 in words is "seventy-eight million, three hundred ninety-one thousand, four".