8443407616821 has 16 divisors (see below), whose sum is σ = 12508928640000. Its totient is φ = 5628858934464.

The previous prime is 8443407616817. The next prime is 8443407616877. The reversal of 8443407616821 is 1286167043448.

8443407616821 is a `hidden beast` number, since 8 + 443 + 40 + 76 + 16 + 82 + 1 = 666.

It is not a de Polignac number, because 8443407616821 - 2² = 8443407616817 is a prime.

It is a super-2 number, since 2×8443407616821² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8443407616801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 227716 + ... + 4115661.

It is an arithmetic number, because the mean of its divisors is an integer number (781808040000).

Almost surely, 2^{8443407616821} is an apocalyptic number.

It is an amenable number.

8443407616821 is a deficient number, since it is larger than the sum of its proper divisors (4065521023179).

8443407616821 is a wasteful number, since it uses less digits than its factorization.

8443407616821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4415385 (or 4415379 counting only the distinct ones).

The product of its (nonzero) digits is 6193152, while the sum is 54.

The spelling of 8443407616821 in words is "eight trillion, four hundred forty-three billion, four hundred seven million, six hundred sixteen thousand, eight hundred twenty-one".