53121101821 has 2 divisors, whose sum is σ = 53121101822. Its totient is φ = 53121101820.

The previous prime is 53121101809. The next prime is 53121101851. The reversal of 53121101821 is 12810112135.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50001879321 + 3119222500 = 223611^2 + 55850^2 .

It is a cyclic number.

It is not a de Polignac number, because 53121101821 - 2¹³ = 53121093629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (53121101801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26560550910 + 26560550911.

It is an arithmetic number, because the mean of its divisors is an integer number (26560550911).

Almost surely, 2^53121101821 is an apocalyptic number.

It is an amenable number.

53121101821 is a deficient number, since it is larger than the sum of its proper divisors (1).

53121101821 is an equidigital number, since it uses as much as digits as its factorization.

53121101821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 25.

Adding to 53121101821 its reverse (12810112135), we get a palindrome (65931213956).

The spelling of 53121101821 in words is "fifty-three billion, one hundred twenty-one million, one hundred one thousand, eight hundred twenty-one".