31204204221 has 4 divisors (see below), whose sum is σ = 41605605632. Its totient is φ = 20802802812.

The previous prime is 31204204193. The next prime is 31204204271. The reversal of 31204204221 is 12240240213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 31204204221 - 2¹⁰ = 31204203197 is a prime.

It is a super-2 number, since 2×31204204221² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31204204271) 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, 5200700701 + ... + 5200700706.

It is an arithmetic number, because the mean of its divisors is an integer number (10401401408).

Almost surely, 2^31204204221 is an apocalyptic number.

It is an amenable number.

31204204221 is a deficient number, since it is larger than the sum of its proper divisors (10401401411).

31204204221 is a wasteful number, since it uses less digits than its factorization.

31204204221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10401401410.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 31204204221 its reverse (12240240213), we get a palindrome (43444444434).

The spelling of 31204204221 in words is "thirty-one billion, two hundred four million, two hundred four thousand, two hundred twenty-one".