20001221311 has 2 divisors, whose sum is σ = 20001221312. Its totient is φ = 20001221310.

The previous prime is 20001221299. The next prime is 20001221351. The reversal of 20001221311 is 11312210002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20001221311 - 2¹³ = 20001213119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20001221291 and 20001221300.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20001221351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000610655 + 10000610656.

It is an arithmetic number, because the mean of its divisors is an integer number (10000610656).

Almost surely, 2^20001221311 is an apocalyptic number.

20001221311 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001221311 is an equidigital number, since it uses as much as digits as its factorization.

20001221311 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 20001221311 its reverse (11312210002), we get a palindrome (31313431313).

The spelling of 20001221311 in words is "twenty billion, one million, two hundred twenty-one thousand, three hundred eleven".