8445643887321 has 9 divisors (see below), whose sum is σ = 12199275986079. Its totient is φ = 5630423445936.

The previous prime is 8445643887301. The next prime is 8445643887377. The reversal of 8445643887321 is 1237883465448.

The square root of 8445643887321 is 2906139.

It is a perfect power (a square), and thus also a powerful number.

8445643887321 is a `hidden beast` number, since 8 + 4 + 4 + 564 + 38 + 8 + 7 + 32 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1843498640025 + 6602145247296 = 1357755^2 + 2569464^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 8445643887321 - 2¹³ = 8445643879129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8445643887301) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 8234061 + ... + 9202773.

Almost surely, 2^{8445643887321} is an apocalyptic number.

8445643887321 is the 2906139-th square number.

8445643887321 is the 1453070-th centered octagonal number.

It is an amenable number.

8445643887321 is a deficient number, since it is larger than the sum of its proper divisors (3753632098758).

8445643887321 is an frugal number, since it uses more digits than its factorization.

8445643887321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1937432 (or 968716 counting only the distinct ones).

The product of its digits is 123863040, while the sum is 63.

The spelling of 8445643887321 in words is "eight trillion, four hundred forty-five billion, six hundred forty-three million, eight hundred eighty-seven thousand, three hundred twenty-one".