78912220 has 24 divisors (see below), whose sum is σ = 166680864. Its totient is φ = 31381056.

The previous prime is 78912217. The next prime is 78912227. The reversal of 78912220 is 2221987.

78912220 = 101² + 102² + ... + 619².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78912227) 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 7 ways as a sum of consecutive naturals, for example, 7944 + ... + 14863.

It is an arithmetic number, because the mean of its divisors is an integer number (6945036).

Almost surely, 2^78912220 is an apocalyptic number.

It is an amenable number.

78912220 is an abundant number, since it is smaller than the sum of its proper divisors (87768644).

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

78912220 is a wasteful number, since it uses less digits than its factorization.

78912220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22989 (or 22987 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 78912220 is about 8883.2550340514. The cubic root of 78912220 is about 428.9250597649.

The spelling of 78912220 in words is "seventy-eight million, nine hundred twelve thousand, two hundred twenty".