78355220 has 12 divisors (see below), whose sum is σ = 164546004. Its totient is φ = 31342080.

The previous prime is 78355219. The next prime is 78355229. The reversal of 78355220 is 2255387.

It can be written as a sum of positive squares in 2 ways, for example, as 45131524 + 33223696 = 6718^2 + 5764^2 .

It is a super-2 number, since 2×78355220² = 12279081002496800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78355229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1958861 + ... + 1958900.

It is an arithmetic number, because the mean of its divisors is an integer number (13712167).

Almost surely, 2^78355220 is an apocalyptic number.

It is an amenable number.

78355220 is an abundant number, since it is smaller than the sum of its proper divisors (86190784).

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

78355220 is a wasteful number, since it uses less digits than its factorization.

78355220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3917770 (or 3917768 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 32.

The square root of 78355220 is about 8851.8483945445. The cubic root of 78355220 is about 427.9134902453.

The spelling of 78355220 in words is "seventy-eight million, three hundred fifty-five thousand, two hundred twenty".