21329911121 has 2 divisors, whose sum is σ = 21329911122. Its totient is φ = 21329911120.

The previous prime is 21329911063. The next prime is 21329911201. The reversal of 21329911121 is 12111992312.

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., 20366429521 + 963481600 = 142711^2 + 31040^2 .

It is a cyclic number.

It is not a de Polignac number, because 21329911121 - 2¹⁰ = 21329910097 is a prime.

It is not a weakly prime, because it can be changed into another prime (21329911021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10664955560 + 10664955561.

It is an arithmetic number, because the mean of its divisors is an integer number (10664955561).

Almost surely, 2^21329911121 is an apocalyptic number.

It is an amenable number.

21329911121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21329911121 is an equidigital number, since it uses as much as digits as its factorization.

21329911121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 32.

The spelling of 21329911121 in words is "twenty-one billion, three hundred twenty-nine million, nine hundred eleven thousand, one hundred twenty-one".