521524402254421 has 2 divisors, whose sum is σ = 521524402254422. Its totient is φ = 521524402254420.

The previous prime is 521524402254409. The next prime is 521524402254461. The reversal of 521524402254421 is 124452204425125.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 478924774922500 + 42599627331921 = 21884350^2 + 6526839^2 .

It is a cyclic number.

It is not a de Polignac number, because 521524402254421 - 2¹⁹ = 521524401730133 is a prime.

It is a super-2 number, since 2×521524402254421² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521524402254461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260762201127210 + 260762201127211.

It is an arithmetic number, because the mean of its divisors is an integer number (260762201127211).

Almost surely, 2^{521524402254421} is an apocalyptic number.

It is an amenable number.

521524402254421 is a deficient number, since it is larger than the sum of its proper divisors (1).

521524402254421 is an equidigital number, since it uses as much as digits as its factorization.

521524402254421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1024000, while the sum is 43.

Adding to 521524402254421 its reverse (124452204425125), we get a palindrome (645976606679546).

The spelling of 521524402254421 in words is "five hundred twenty-one trillion, five hundred twenty-four billion, four hundred two million, two hundred fifty-four thousand, four hundred twenty-one".