31201203121 has 4 divisors (see below), whose sum is σ = 34037676144. Its totient is φ = 28364730100.

The previous prime is 31201203097. The next prime is 31201203151. The reversal of 31201203121 is 12130210213.

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 31201203121 - 2⁷ = 31201202993 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31201203095 and 31201203104.

It is not an unprimeable number, because it can be changed into a prime (31201203151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1418236495 + ... + 1418236516.

It is an arithmetic number, because the mean of its divisors is an integer number (8509419036).

Almost surely, 2^31201203121 is an apocalyptic number.

It is an amenable number.

31201203121 is a deficient number, since it is larger than the sum of its proper divisors (2836473023).

31201203121 is a wasteful number, since it uses less digits than its factorization.

31201203121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2836473022.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 31201203121 its reverse (12130210213), we get a palindrome (43331413334).

The spelling of 31201203121 in words is "thirty-one billion, two hundred one million, two hundred three thousand, one hundred twenty-one".