506561625421 has 2 divisors, whose sum is σ = 506561625422. Its totient is φ = 506561625420.

The previous prime is 506561625391. The next prime is 506561625443. The reversal of 506561625421 is 124526165605.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 392934654025 + 113626971396 = 626845^2 + 337086^2 .

It is a cyclic number.

It is not a de Polignac number, because 506561625421 - 2⁵ = 506561625389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (506561625821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 253280812710 + 253280812711.

It is an arithmetic number, because the mean of its divisors is an integer number (253280812711).

Almost surely, 2^506561625421 is an apocalyptic number.

It is an amenable number.

506561625421 is a deficient number, since it is larger than the sum of its proper divisors (1).

506561625421 is an equidigital number, since it uses as much as digits as its factorization.

506561625421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432000, while the sum is 43.

The spelling of 506561625421 in words is "five hundred six billion, five hundred sixty-one million, six hundred twenty-five thousand, four hundred twenty-one".