78123918 has 8 divisors (see below), whose sum is σ = 156247848. Its totient is φ = 26041304.

The previous prime is 78123911. The next prime is 78123919. The reversal of 78123918 is 81932187.

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

78123918 is an admirable number.

It is a super-2 number, since 2×78123918² = 12206693127341448, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78123911) 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 3 ways as a sum of consecutive naturals, for example, 6510321 + ... + 6510332.

It is an arithmetic number, because the mean of its divisors is an integer number (19530981).

Almost surely, 2^78123918 is an apocalyptic number.

78123918 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78123918 is a wasteful number, since it uses less digits than its factorization.

78123918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13020658.

The product of its digits is 24192, while the sum is 39.

The square root of 78123918 is about 8838.7735574569. The cubic root of 78123918 is about 427.4920131198.

The spelling of 78123918 in words is "seventy-eight million, one hundred twenty-three thousand, nine hundred eighteen".