31221130013 has 4 divisors (see below), whose sum is σ = 31947202848. Its totient is φ = 30495057180.

The previous prime is 31221129991. The next prime is 31221130027. The reversal of 31221130013 is 31003112213.

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 31221130013 - 2¹² = 31221125917 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31221129973 and 31221130000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31221130043) 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, 363036353 + ... + 363036438.

It is an arithmetic number, because the mean of its divisors is an integer number (7986800712).

Almost surely, 2^31221130013 is an apocalyptic number.

It is an amenable number.

31221130013 is a deficient number, since it is larger than the sum of its proper divisors (726072835).

31221130013 is an equidigital number, since it uses as much as digits as its factorization.

31221130013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726072834.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 31221130013 its reverse (31003112213), we get a palindrome (62224242226).

The spelling of 31221130013 in words is "thirty-one billion, two hundred twenty-one million, one hundred thirty thousand, thirteen".