21230421139 has 4 divisors (see below), whose sum is σ = 21238772256. Its totient is φ = 21222070024.

The previous prime is 21230421133. The next prime is 21230421161. The reversal of 21230421139 is 93112403212.

It is a happy number.

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 21230421139 - 2³ = 21230421131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21230421131) 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, 4171744 + ... + 4176829.

It is an arithmetic number, because the mean of its divisors is an integer number (5309693064).

Almost surely, 2^21230421139 is an apocalyptic number.

21230421139 is a deficient number, since it is larger than the sum of its proper divisors (8351117).

21230421139 is an equidigital number, since it uses as much as digits as its factorization.

21230421139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8351116.

The product of its (nonzero) digits is 2592, while the sum is 28.

The spelling of 21230421139 in words is "twenty-one billion, two hundred thirty million, four hundred twenty-one thousand, one hundred thirty-nine".