8438778820 has 12 divisors (see below), whose sum is σ = 17721435564. Its totient is φ = 3375511520.

The previous prime is 8438778809. The next prime is 8438778823. The reversal of 8438778820 is 288778348.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 5881049344 + 2557729476 = 76688^2 + 50574^2 .

It is not an unprimeable number, because it can be changed into a prime (8438778823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210969451 + ... + 210969490.

It is an arithmetic number, because the mean of its divisors is an integer number (1476786297).

Almost surely, 2^8438778820 is an apocalyptic number.

It is an amenable number.

8438778820 is an abundant number, since it is smaller than the sum of its proper divisors (9282656744).

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

8438778820 is a wasteful number, since it uses less digits than its factorization.

8438778820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421938950 (or 421938948 counting only the distinct ones).

The product of its (nonzero) digits is 4816896, while the sum is 55.

The square root of 8438778820 is about 91862.8261050138. The cubic root of 8438778820 is about 2035.9160591478.

The spelling of 8438778820 in words is "eight billion, four hundred thirty-eight million, seven hundred seventy-eight thousand, eight hundred twenty".