521154344109961 has 2 divisors, whose sum is σ = 521154344109962. Its totient is φ = 521154344109960.

The previous prime is 521154344109913. The next prime is 521154344110051. The reversal of 521154344109961 is 169901443451125.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 278968695950736 + 242185648159225 = 16702356^2 + 15562315^2 .

It is a cyclic number.

It is not a de Polignac number, because 521154344109961 - 2¹⁷ = 521154343978889 is a prime.

It is not a weakly prime, because it can be changed into another prime (521154344101961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260577172054980 + 260577172054981.

It is an arithmetic number, because the mean of its divisors is an integer number (260577172054981).

Almost surely, 2^{521154344109961} is an apocalyptic number.

It is an amenable number.

521154344109961 is a deficient number, since it is larger than the sum of its proper divisors (1).

521154344109961 is an equidigital number, since it uses as much as digits as its factorization.

521154344109961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4665600, while the sum is 55.

The spelling of 521154344109961 in words is "five hundred twenty-one trillion, one hundred fifty-four billion, three hundred forty-four million, one hundred nine thousand, nine hundred sixty-one".