99717421 has 4 divisors (see below), whose sum is σ = 102934144. Its totient is φ = 96500700.

The previous prime is 99717419. The next prime is 99717437. The reversal of 99717421 is 12471799.

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 not a de Polignac number, because 99717421 - 2¹ = 99717419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99717481) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1608315 + ... + 1608376.

It is an arithmetic number, because the mean of its divisors is an integer number (25733536).

Almost surely, 2^99717421 is an apocalyptic number.

It is an amenable number.

99717421 is a deficient number, since it is larger than the sum of its proper divisors (3216723).

99717421 is a wasteful number, since it uses less digits than its factorization.

99717421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3216722.

The product of its digits is 31752, while the sum is 40.

The square root of 99717421 is about 9985.8610545110. The cubic root of 99717421 is about 463.7212657199.

The spelling of 99717421 in words is "ninety-nine million, seven hundred seventeen thousand, four hundred twenty-one".