513840121 has 2 divisors, whose sum is σ = 513840122. Its totient is φ = 513840120.

The previous prime is 513840073. The next prime is 513840133. The reversal of 513840121 is 121048315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 316128400 + 197711721 = 17780^2 + 14061^2 .

It is a cyclic number.

It is not a de Polignac number, because 513840121 - 2¹⁵ = 513807353 is a prime.

It is not a weakly prime, because it can be changed into another prime (513840191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 256920060 + 256920061.

It is an arithmetic number, because the mean of its divisors is an integer number (256920061).

Almost surely, 2^513840121 is an apocalyptic number.

It is an amenable number.

513840121 is a deficient number, since it is larger than the sum of its proper divisors (1).

513840121 is an equidigital number, since it uses as much as digits as its factorization.

513840121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 513840121 is about 22668.0418430883. The cubic root of 513840121 is about 800.9572504867.

Adding to 513840121 its reverse (121048315), we get a palindrome (634888436).

The spelling of 513840121 in words is "five hundred thirteen million, eight hundred forty thousand, one hundred twenty-one".