78178920 has 128 divisors (see below), whose sum is σ = 261532800. Its totient is φ = 18579456.

The previous prime is 78178897. The next prime is 78178921. The reversal of 78178920 is 2987187.

It is a super-3 number, since 3×78178920³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (78178921) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 37752 + ... + 39768.

It is an arithmetic number, because the mean of its divisors is an integer number (2043225).

Almost surely, 2^78178920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78178920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130766400).

78178920 is an abundant number, since it is smaller than the sum of its proper divisors (183353880).

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

78178920 is a wasteful number, since it uses less digits than its factorization.

78178920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2067 (or 2063 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 42.

The square root of 78178920 is about 8841.8844145352. The cubic root of 78178920 is about 427.5923127485.

The spelling of 78178920 in words is "seventy-eight million, one hundred seventy-eight thousand, nine hundred twenty".