21204202042231 has 4 divisors (see below), whose sum is σ = 22835294507032. Its totient is φ = 19573109577432.

The previous prime is 21204202042213. The next prime is 21204202042253. The reversal of 21204202042231 is 13224020240212.

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 21204202042231 - 2³¹ = 21202054558583 is a prime.

It is a super-2 number, since 2×21204202042231² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21204202042196 and 21204202042205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204202042931) 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, 815546232381 + ... + 815546232406.

It is an arithmetic number, because the mean of its divisors is an integer number (5708823626758).

Almost surely, 2^{21204202042231} is an apocalyptic number.

21204202042231 is a deficient number, since it is larger than the sum of its proper divisors (1631092464801).

21204202042231 is a wasteful number, since it uses less digits than its factorization.

21204202042231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1631092464800.

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21204202042231 its reverse (13224020240212), we get a palindrome (34428222282443).

The spelling of 21204202042231 in words is "twenty-one trillion, two hundred four billion, two hundred two million, forty-two thousand, two hundred thirty-one".