521721127061 has 2 divisors, whose sum is σ = 521721127062. Its totient is φ = 521721127060.

The previous prime is 521721127051. The next prime is 521721127063. The reversal of 521721127061 is 160721127125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 307990590961 + 213730536100 = 554969^2 + 462310^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521721127061 is a prime.

Together with 521721127063, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521721127063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260860563530 + 260860563531.

It is an arithmetic number, because the mean of its divisors is an integer number (260860563531).

Almost surely, 2^521721127061 is an apocalyptic number.

It is an amenable number.

521721127061 is a deficient number, since it is larger than the sum of its proper divisors (1).

521721127061 is an equidigital number, since it uses as much as digits as its factorization.

521721127061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11760, while the sum is 35.

The spelling of 521721127061 in words is "five hundred twenty-one billion, seven hundred twenty-one million, one hundred twenty-seven thousand, sixty-one".