31330220221 has 4 divisors (see below), whose sum is σ = 32979179200. Its totient is φ = 29681261244.

The previous prime is 31330220219. The next prime is 31330220231. The reversal of 31330220221 is 12202203313.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12202203313 = 19 ⋅642221227.

It is a cyclic number.

It is not a de Polignac number, because 31330220221 - 2¹ = 31330220219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 1648958959 = 31330220221 / (3 + 1 + 3 + 3 + 0 + 2 + 2 + 0 + 2 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31330220231) 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, 824479461 + ... + 824479498.

It is an arithmetic number, because the mean of its divisors is an integer number (8244794800).

Almost surely, 2^31330220221 is an apocalyptic number.

It is an amenable number.

31330220221 is a deficient number, since it is larger than the sum of its proper divisors (1648958979).

31330220221 is a wasteful number, since it uses less digits than its factorization.

31330220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1648958978.

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 31330220221 its reverse (12202203313), we get a palindrome (43532423534).

The spelling of 31330220221 in words is "thirty-one billion, three hundred thirty million, two hundred twenty thousand, two hundred twenty-one".