8761221820 has 24 divisors (see below), whose sum is σ = 19813840704. Its totient is φ = 3234912576.

The previous prime is 8761221797. The next prime is 8761221853. The reversal of 8761221820 is 281221678.

It is a super-2 number, since 2×8761221820² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 8761221820.

It is a congruent number.

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, 16848244 + ... + 16848763.

It is an arithmetic number, because the mean of its divisors is an integer number (825576696).

Almost surely, 2^8761221820 is an apocalyptic number.

It is an amenable number.

8761221820 is an abundant number, since it is smaller than the sum of its proper divisors (11052618884).

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

8761221820 is a wasteful number, since it uses less digits than its factorization.

8761221820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33697029 (or 33697027 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 8761221820 is about 93601.3986006619. The cubic root of 8761221820 is about 2061.5231939960.

The spelling of 8761221820 in words is "eight billion, seven hundred sixty-one million, two hundred twenty-one thousand, eight hundred twenty".