78865920 has 320 divisors, whose sum is σ = 322122240. Its totient is φ = 17915904.

The previous prime is 78865883. The next prime is 78865921. The reversal of 78865920 is 2956887.

78865920 = T₂₇₉ + T₂₈₀ + ... + T₇₉₀.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78865921) 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, 483759 + ... + 483921.

It is an arithmetic number, because the mean of its divisors is an integer number (1006632).

Almost surely, 2^78865920 is an apocalyptic number.

78865920 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78865920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161061120).

78865920 is an abundant number, since it is smaller than the sum of its proper divisors (243256320).

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

78865920 is a wasteful number, since it uses less digits than its factorization.

78865920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The square root of 78865920 is about 8880.6486249598. The cubic root of 78865920 is about 428.8411559220.

The spelling of 78865920 in words is "seventy-eight million, eight hundred sixty-five thousand, nine hundred twenty".