20213231311121 has 2 divisors, whose sum is σ = 20213231311122. Its totient is φ = 20213231311120.

The previous prime is 20213231311099. The next prime is 20213231311151. The reversal of 20213231311121 is 12111313231202.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17806501050625 + 2406730260496 = 4219775^2 + 1551364^2 .

It is a cyclic number.

It is not a de Polignac number, because 20213231311121 - 2¹⁸ = 20213231048977 is a prime.

It is not a weakly prime, because it can be changed into another prime (20213231311151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10106615655560 + 10106615655561.

It is an arithmetic number, because the mean of its divisors is an integer number (10106615655561).

Almost surely, 2^{20213231311121} is an apocalyptic number.

It is an amenable number.

20213231311121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20213231311121 is an equidigital number, since it uses as much as digits as its factorization.

20213231311121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 20213231311121 its reverse (12111313231202), we get a palindrome (32324544542323).

The spelling of 20213231311121 in words is "twenty trillion, two hundred thirteen billion, two hundred thirty-one million, three hundred eleven thousand, one hundred twenty-one".