8421771840 has 56 divisors (see below), whose sum is σ = 26739128640. Its totient is φ = 2245805568.

The previous prime is 8421771833. The next prime is 8421771857. The reversal of 8421771840 is 481771248.

It is a junction number, because it is equal to n+sod(n) for n = 8421771792 and 8421771801.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4385380 + ... + 4387299.

It is an arithmetic number, because the mean of its divisors is an integer number (477484440).

Almost surely, 2^8421771840 is an apocalyptic number.

8421771840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8421771840 is an abundant number, since it is smaller than the sum of its proper divisors (18317356800).

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

8421771840 is a wasteful number, since it uses less digits than its factorization.

8421771840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8772699 (or 8772689 counting only the distinct ones).

The product of its (nonzero) digits is 100352, while the sum is 42.

The square root of 8421771840 is about 91770.2121605916. The cubic root of 8421771840 is about 2034.5474539378.

The spelling of 8421771840 in words is "eight billion, four hundred twenty-one million, seven hundred seventy-one thousand, eight hundred forty".