31031213003121 has 4 divisors (see below), whose sum is σ = 41374950670832. Its totient is φ = 20687475335412.

The previous prime is 31031213003111. The next prime is 31031213003143. The reversal of 31031213003121 is 12130031213013.

It is a happy number.

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 31031213003121 - 2²⁷ = 31031078785393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31031213003101) 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, 5171868833851 + ... + 5171868833856.

It is an arithmetic number, because the mean of its divisors is an integer number (10343737667708).

Almost surely, 2^{31031213003121} is an apocalyptic number.

It is an amenable number.

31031213003121 is a deficient number, since it is larger than the sum of its proper divisors (10343737667711).

31031213003121 is a wasteful number, since it uses less digits than its factorization.

31031213003121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10343737667710.

The product of its (nonzero) digits is 324, while the sum is 21.

Adding to 31031213003121 its reverse (12130031213013), we get a palindrome (43161244216134).

The spelling of 31031213003121 in words is "thirty-one trillion, thirty-one billion, two hundred thirteen million, three thousand, one hundred twenty-one".