20311331221001 has 2 divisors, whose sum is σ = 20311331221002. Its totient is φ = 20311331221000.

The previous prime is 20311331220893. The next prime is 20311331221021. The reversal of 20311331221001 is 10012213311302.

It is a happy number.

It is an a-pointer prime, because the next prime (20311331221021) can be obtained adding 20311331221001 to its sum of digits (20).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17647972500601 + 2663358720400 = 4200949^2 + 1631980^2 .

It is a cyclic number.

It is not a de Polignac number, because 20311331221001 - 2³⁸ = 20036453314057 is a prime.

It is not a weakly prime, because it can be changed into another prime (20311331221021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10155665610500 + 10155665610501.

It is an arithmetic number, because the mean of its divisors is an integer number (10155665610501).

Almost surely, 2^{20311331221001} is an apocalyptic number.

It is an amenable number.

20311331221001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20311331221001 is an equidigital number, since it uses as much as digits as its factorization.

20311331221001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 20311331221001 its reverse (10012213311302), we get a palindrome (30323544532303).

The spelling of 20311331221001 in words is "twenty trillion, three hundred eleven billion, three hundred thirty-one million, two hundred twenty-one thousand, one".