78278889 has 8 divisors (see below), whose sum is σ = 112400512. Its totient is φ = 48171600.

The previous prime is 78278887. The next prime is 78278891. The reversal of 78278889 is 98887287.

It is an interprime number because it is at equal distance from previous prime (78278887) and next prime (78278891).

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

It is not a de Polignac number, because 78278889 - 2¹ = 78278887 is a prime.

It is a super-2 number, since 2×78278889² = 12255168926148642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78278887) 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 7 ways as a sum of consecutive naturals, for example, 1003537 + ... + 1003614.

It is an arithmetic number, because the mean of its divisors is an integer number (14050064).

Almost surely, 2^78278889 is an apocalyptic number.

It is an amenable number.

78278889 is a deficient number, since it is larger than the sum of its proper divisors (34121623).

78278889 is a wasteful number, since it uses less digits than its factorization.

78278889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2007167.

The product of its digits is 3612672, while the sum is 57.

The square root of 78278889 is about 8847.5357586166. The cubic root of 78278889 is about 427.7744921594.

The spelling of 78278889 in words is "seventy-eight million, two hundred seventy-eight thousand, eight hundred eighty-nine".