20535943121 has 2 divisors, whose sum is σ = 20535943122. Its totient is φ = 20535943120.

The previous prime is 20535943117. The next prime is 20535943163. The reversal of 20535943121 is 12134953502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15471628225 + 5064314896 = 124385^2 + 71164^2 .

It is a cyclic number.

It is not a de Polignac number, because 20535943121 - 2² = 20535943117 is a prime.

It is not a weakly prime, because it can be changed into another prime (20535943111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10267971560 + 10267971561.

It is an arithmetic number, because the mean of its divisors is an integer number (10267971561).

Almost surely, 2^20535943121 is an apocalyptic number.

It is an amenable number.

20535943121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20535943121 is an equidigital number, since it uses as much as digits as its factorization.

20535943121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 35.

The spelling of 20535943121 in words is "twenty billion, five hundred thirty-five million, nine hundred forty-three thousand, one hundred twenty-one".