31221213321 has 8 divisors (see below), whose sum is σ = 41650830144. Its totient is φ = 20802869360.

The previous prime is 31221213319. The next prime is 31221213367. The reversal of 31221213321 is 12331212213.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31221213321 - 2¹ = 31221213319 is a prime.

It is a super-2 number, since 2×31221213321² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31221213301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2811750 + ... + 2822831.

It is an arithmetic number, because the mean of its divisors is an integer number (5206353768).

Almost surely, 2^31221213321 is an apocalyptic number.

It is an amenable number.

31221213321 is a deficient number, since it is larger than the sum of its proper divisors (10429616823).

31221213321 is a wasteful number, since it uses less digits than its factorization.

31221213321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5636431.

The product of its digits is 432, while the sum is 21.

Adding to 31221213321 its reverse (12331212213), we get a palindrome (43552425534).

The spelling of 31221213321 in words is "thirty-one billion, two hundred twenty-one million, two hundred thirteen thousand, three hundred twenty-one".