31230012221 has 4 divisors (see below), whose sum is σ = 31421607552. Its totient is φ = 31038416892.

The previous prime is 31230012161. The next prime is 31230012241. The reversal of 31230012221 is 12221003213.

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 a de Polignac number, because none of the positive numbers 2^k-31230012221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31230012221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31230012241) 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, 95797421 + ... + 95797746.

It is an arithmetic number, because the mean of its divisors is an integer number (7855401888).

Almost surely, 2^31230012221 is an apocalyptic number.

It is an amenable number.

31230012221 is a deficient number, since it is larger than the sum of its proper divisors (191595331).

31230012221 is a wasteful number, since it uses less digits than its factorization.

31230012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191595330.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 31230012221 its reverse (12221003213), we get a palindrome (43451015434).

The spelling of 31230012221 in words is "thirty-one billion, two hundred thirty million, twelve thousand, two hundred twenty-one".