78057220 has 12 divisors (see below), whose sum is σ = 163920204. Its totient is φ = 31222880.

The previous prime is 78057179. The next prime is 78057223. The reversal of 78057220 is 2275087.

It can be written as a sum of positive squares in 2 ways, for example, as 19289664 + 58767556 = 4392^2 + 7666^2 .

It is not an unprimeable number, because it can be changed into a prime (78057223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1951411 + ... + 1951450.

It is an arithmetic number, because the mean of its divisors is an integer number (13660017).

Almost surely, 2^78057220 is an apocalyptic number.

It is an amenable number.

78057220 is an abundant number, since it is smaller than the sum of its proper divisors (85862984).

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

78057220 is a wasteful number, since it uses less digits than its factorization.

78057220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3902870 (or 3902868 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 31.

The square root of 78057220 is about 8834.9997170345. Note that the first 3 decimals coincide. The cubic root of 78057220 is about 427.3703219181.

The spelling of 78057220 in words is "seventy-eight million, fifty-seven thousand, two hundred twenty".