521321621489 has 2 divisors, whose sum is σ = 521321621490. Its totient is φ = 521321621488.

The previous prime is 521321621467. The next prime is 521321621497. The reversal of 521321621489 is 984126123125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 476465770225 + 44855851264 = 690265^2 + 211792^2 .

It is a cyclic number.

It is not a de Polignac number, because 521321621489 - 2²⁸ = 521053186033 is a prime.

It is not a weakly prime, because it can be changed into another prime (521321621389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260660810744 + 260660810745.

It is an arithmetic number, because the mean of its divisors is an integer number (260660810745).

Almost surely, 2^521321621489 is an apocalyptic number.

It is an amenable number.

521321621489 is a deficient number, since it is larger than the sum of its proper divisors (1).

521321621489 is an equidigital number, since it uses as much as digits as its factorization.

521321621489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 44.

The spelling of 521321621489 in words is "five hundred twenty-one billion, three hundred twenty-one million, six hundred twenty-one thousand, four hundred eighty-nine".