99640421 has 8 divisors (see below), whose sum is σ = 101025120. Its totient is φ = 98260272.

The previous prime is 99640403. The next prime is 99640441. The reversal of 99640421 is 12404699.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99640421 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 (99640441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88166 + ... + 89288.

It is an arithmetic number, because the mean of its divisors is an integer number (12628140).

Almost surely, 2^99640421 is an apocalyptic number.

It is an amenable number.

99640421 is a deficient number, since it is larger than the sum of its proper divisors (1384699).

99640421 is a wasteful number, since it uses less digits than its factorization.

99640421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2275.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 99640421 is about 9982.0048587446. The cubic root of 99640421 is about 463.6018759092.

The spelling of 99640421 in words is "ninety-nine million, six hundred forty thousand, four hundred twenty-one".