99943867420921 has 4 divisors (see below), whose sum is σ = 99943894861200. Its totient is φ = 99943839980644.

The previous prime is 99943867420883. The next prime is 99943867420961. The reversal of 99943867420921 is 12902476834999.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99943867420921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99943867420961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7235011 + ... + 15881848.

It is an arithmetic number, because the mean of its divisors is an integer number (24985973715300).

Almost surely, 2^{99943867420921} is an apocalyptic number.

It is an amenable number.

99943867420921 is a deficient number, since it is larger than the sum of its proper divisors (27440279).

99943867420921 is a wasteful number, since it uses less digits than its factorization.

99943867420921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27440278.

The product of its (nonzero) digits is 423263232, while the sum is 73.

The spelling of 99943867420921 in words is "ninety-nine trillion, nine hundred forty-three billion, eight hundred sixty-seven million, four hundred twenty thousand, nine hundred twenty-one".