78487220 has 54 divisors (see below), whose sum is σ = 192412962. Its totient is φ = 26814816.

The previous prime is 78487187. The next prime is 78487273. The reversal of 78487220 is 2278487.

It can be written as a sum of positive squares in only one way, i.e., 62789776 + 15697444 = 7924^2 + 3962^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 277199 + ... + 277481.

It is an arithmetic number, because the mean of its divisors is an integer number (3563203).

Almost surely, 2^78487220 is an apocalyptic number.

78487220 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 78487220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96206481).

78487220 is an abundant number, since it is smaller than the sum of its proper divisors (113925742).

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

78487220 is a wasteful number, since it uses less digits than its factorization.

78487220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 589 (or 297 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 38.

The square root of 78487220 is about 8859.3013268542. The cubic root of 78487220 is about 428.1536482153.

The spelling of 78487220 in words is "seventy-eight million, four hundred eighty-seven thousand, two hundred twenty".