31431204121 has 4 divisors (see below), whose sum is σ = 31431635200. Its totient is φ = 31430773044.

The previous prime is 31431204109. The next prime is 31431204131. The reversal of 31431204121 is 12140213413.

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 a cyclic number.

It is not a de Polignac number, because 31431204121 - 2¹⁷ = 31431073049 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31431204092 and 31431204101.

It is not an unprimeable number, because it can be changed into a prime (31431204131) 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, 76101 + ... + 262018.

It is an arithmetic number, because the mean of its divisors is an integer number (7857908800).

Almost surely, 2^31431204121 is an apocalyptic number.

It is an amenable number.

31431204121 is a deficient number, since it is larger than the sum of its proper divisors (431079).

31431204121 is an equidigital number, since it uses as much as digits as its factorization.

31431204121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431078.

The product of its (nonzero) digits is 576, while the sum is 22.

Adding to 31431204121 its reverse (12140213413), we get a palindrome (43571417534).

The spelling of 31431204121 in words is "thirty-one billion, four hundred thirty-one million, two hundred four thousand, one hundred twenty-one".