78913989 has 48 divisors (see below), whose sum is σ = 148322304. Its totient is φ = 39204000.

The previous prime is 78913981. The next prime is 78913999. The reversal of 78913989 is 98931987.

It is not a de Polignac number, because 78913989 - 2³ = 78913981 is a prime.

It is a super-3 number, since 3×78913989³ (a number of 25 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78913981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13464 + ... + 18414.

It is an arithmetic number, because the mean of its divisors is an integer number (3090048).

Almost surely, 2^78913989 is an apocalyptic number.

It is an amenable number.

78913989 is a deficient number, since it is larger than the sum of its proper divisors (69408315).

78913989 is a wasteful number, since it uses less digits than its factorization.

78913989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4998 (or 4995 counting only the distinct ones).

The product of its digits is 979776, while the sum is 54.

The square root of 78913989 is about 8883.3546028513. The cubic root of 78913989 is about 428.9282648568.

The spelling of 78913989 in words is "seventy-eight million, nine hundred thirteen thousand, nine hundred eighty-nine".