78130920 has 128 divisors (see below), whose sum is σ = 273715200. Its totient is φ = 17469696.

The previous prime is 78130891. The next prime is 78130933. The reversal of 78130920 is 2903187.

It is a happy number.

It is a super-2 number, since 2×78130920² = 12208881320092800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38491 + ... + 40469.

It is an arithmetic number, because the mean of its divisors is an integer number (2138400).

Almost surely, 2^78130920 is an apocalyptic number.

78130920 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 78130920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136857600).

78130920 is an abundant number, since it is smaller than the sum of its proper divisors (195584280).

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

78130920 is a wasteful number, since it uses less digits than its factorization.

78130920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2047 (or 2043 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 78130920 is about 8839.1696442596. The cubic root of 78130920 is about 427.5047843246.

The spelling of 78130920 in words is "seventy-eight million, one hundred thirty thousand, nine hundred twenty".