99789421 has 4 divisors (see below), whose sum is σ = 99810172. Its totient is φ = 99768672.

The previous prime is 99789419. The next prime is 99789451. The reversal of 99789421 is 12498799.

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

It can be written as a sum of positive squares in 2 ways, for example, as 88566921 + 11222500 = 9411^2 + 3350^2 .

It is a cyclic number.

It is not a de Polignac number, because 99789421 - 2¹ = 99789419 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 (99789401) 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, 985 + ... + 14161.

It is an arithmetic number, because the mean of its divisors is an integer number (24952543).

Almost surely, 2^99789421 is an apocalyptic number.

It is an amenable number.

99789421 is a deficient number, since it is larger than the sum of its proper divisors (20751).

99789421 is a wasteful number, since it uses less digits than its factorization.

99789421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20750.

The product of its digits is 326592, while the sum is 49.

The square root of 99789421 is about 9989.4655012168. The cubic root of 99789421 is about 463.8328473546.

The spelling of 99789421 in words is "ninety-nine million, seven hundred eighty-nine thousand, four hundred twenty-one".