31111320221 has 8 divisors (see below), whose sum is σ = 31632395040. Its totient is φ = 30591913968.

The previous prime is 31111320217. The next prime is 31111320301. The reversal of 31111320221 is 12202311113.

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 31111320221 - 2² = 31111320217 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 31111320221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31111320211) 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, 379511 + ... + 454148.

It is an arithmetic number, because the mean of its divisors is an integer number (3954049380).

Almost surely, 2^31111320221 is an apocalyptic number.

It is an amenable number.

31111320221 is a deficient number, since it is larger than the sum of its proper divisors (521074819).

31111320221 is an equidigital number, since it uses as much as digits as its factorization.

31111320221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834283.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 31111320221 its reverse (12202311113), we get a palindrome (43313631334).

The spelling of 31111320221 in words is "thirty-one billion, one hundred eleven million, three hundred twenty thousand, two hundred twenty-one".