515721461 has 2 divisors, whose sum is σ = 515721462. Its totient is φ = 515721460.

The previous prime is 515721439. The next prime is 515721509. The reversal of 515721461 is 164127515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 376127236 + 139594225 = 19394^2 + 11815^2 .

It is a cyclic number.

It is not a de Polignac number, because 515721461 - 2²⁶ = 448612597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (515721431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 257860730 + 257860731.

It is an arithmetic number, because the mean of its divisors is an integer number (257860731).

Almost surely, 2^515721461 is an apocalyptic number.

It is an amenable number.

515721461 is a deficient number, since it is larger than the sum of its proper divisors (1).

515721461 is an equidigital number, since it uses as much as digits as its factorization.

515721461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8400, while the sum is 32.

The square root of 515721461 is about 22709.5015577181. The cubic root of 515721461 is about 801.9335837397.

Adding to 515721461 its reverse (164127515), we get a palindrome (679848976).

The spelling of 515721461 in words is "five hundred fifteen million, seven hundred twenty-one thousand, four hundred sixty-one".