8921220381 has 96 divisors (see below), whose sum is σ = 14488830720. Its totient is φ = 5269017600.

The previous prime is 8921220313. The next prime is 8921220383. The reversal of 8921220381 is 1830221298.

8921220381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 8921220381 - 2²³ = 8912831773 is a prime.

It is a super-2 number, since 2×8921220381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8921220383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 16489971 + ... + 16490511.

It is an arithmetic number, because the mean of its divisors is an integer number (150925320).

Almost surely, 2^8921220381 is an apocalyptic number.

It is an amenable number.

8921220381 is a deficient number, since it is larger than the sum of its proper divisors (5567610339).

8921220381 is a wasteful number, since it uses less digits than its factorization.

8921220381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 707 (or 704 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 8921220381 is about 94452.2121551422. The cubic root of 8921220381 is about 2073.9968349576.

The spelling of 8921220381 in words is "eight billion, nine hundred twenty-one million, two hundred twenty thousand, three hundred eighty-one".