78449220 has 144 divisors (see below), whose sum is σ = 260402688. Its totient is φ = 19031040.

The previous prime is 78449209. The next prime is 78449221. The reversal of 78449220 is 2294487.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (78449221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 94447 + ... + 95273.

It is an arithmetic number, because the mean of its divisors is an integer number (1808352).

Almost surely, 2^78449220 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78449220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130201344).

78449220 is an abundant number, since it is smaller than the sum of its proper divisors (181953468).

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

78449220 is a wasteful number, since it uses less digits than its factorization.

78449220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 890 (or 885 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 78449220 is about 8857.1564285610. The cubic root of 78449220 is about 428.0845394480.

The spelling of 78449220 in words is "seventy-eight million, four hundred forty-nine thousand, two hundred twenty".