10521544515421 has 2 divisors, whose sum is σ = 10521544515422. Its totient is φ = 10521544515420.

The previous prime is 10521544515413. The next prime is 10521544515479. The reversal of 10521544515421 is 12451544512501.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10328902527321 + 192641988100 = 3213861^2 + 438910^2 .

It is a cyclic number.

It is not a de Polignac number, because 10521544515421 - 2³ = 10521544515413 is a prime.

It is a super-2 number, since 2×10521544515421² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10521544515491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5260772257710 + 5260772257711.

It is an arithmetic number, because the mean of its divisors is an integer number (5260772257711).

Almost surely, 2^{10521544515421} is an apocalyptic number.

It is an amenable number.

10521544515421 is a deficient number, since it is larger than the sum of its proper divisors (1).

10521544515421 is an equidigital number, since it uses as much as digits as its factorization.

10521544515421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 160000, while the sum is 40.

The spelling of 10521544515421 in words is "ten trillion, five hundred twenty-one billion, five hundred forty-four million, five hundred fifteen thousand, four hundred twenty-one".