99971321 has 4 divisors (see below), whose sum is σ = 100530000. Its totient is φ = 99412644.

The previous prime is 99971309. The next prime is 99971327. The reversal of 99971321 is 12317999.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12317999 = 41 ⋅300439.

It is a cyclic number.

It is not a de Polignac number, because 99971321 - 2⁶ = 99971257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99971327) 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 3 ways as a sum of consecutive naturals, for example, 279071 + ... + 279428.

It is an arithmetic number, because the mean of its divisors is an integer number (25132500).

Almost surely, 2^99971321 is an apocalyptic number.

It is an amenable number.

99971321 is a deficient number, since it is larger than the sum of its proper divisors (558679).

99971321 is a wasteful number, since it uses less digits than its factorization.

99971321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 558678.

The product of its digits is 30618, while the sum is 41.

The square root of 99971321 is about 9998.5659471746. The cubic root of 99971321 is about 464.1145070767.

The spelling of 99971321 in words is "ninety-nine million, nine hundred seventy-one thousand, three hundred twenty-one".