78415920 has 120 divisors (see below), whose sum is σ = 287316432. Its totient is φ = 19008000.

The previous prime is 78415919. The next prime is 78415933. The reversal of 78415920 is 2951487.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×78415920² = 12298113018892800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2970 + ... + 12870.

Almost surely, 2^78415920 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 78415920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143658216).

78415920 is an abundant number, since it is smaller than the sum of its proper divisors (208900512).

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

78415920 is a wasteful number, since it uses less digits than its factorization.

78415920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9931 (or 9922 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 78415920 is about 8855.2763932020. The cubic root of 78415920 is about 428.0239599944.

The spelling of 78415920 in words is "seventy-eight million, four hundred fifteen thousand, nine hundred twenty".