99405391 has 4 divisors (see below), whose sum is σ = 99427392. Its totient is φ = 99383392.

The previous prime is 99405389. The next prime is 99405407. The reversal of 99405391 is 19350499.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 99405391 - 2¹ = 99405389 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99405331) 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, 1471 + ... + 14176.

It is an arithmetic number, because the mean of its divisors is an integer number (24856848).

Almost surely, 2^99405391 is an apocalyptic number.

99405391 is a deficient number, since it is larger than the sum of its proper divisors (22001).

99405391 is a wasteful number, since it uses less digits than its factorization.

99405391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22000.

The product of its (nonzero) digits is 43740, while the sum is 40.

The square root of 99405391 is about 9970.2252231331. The cubic root of 99405391 is about 463.2370770606.

The spelling of 99405391 in words is "ninety-nine million, four hundred five thousand, three hundred ninety-one".