12521643643 has 2 divisors, whose sum is σ = 12521643644. Its totient is φ = 12521643642.

The previous prime is 12521643611. The next prime is 12521643653. The reversal of 12521643643 is 34634612521.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12521643643 - 2⁵ = 12521643611 is a prime.

It is a super-2 number, since 2×12521643643² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (12521643653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6260821821 + 6260821822.

It is an arithmetic number, because the mean of its divisors is an integer number (6260821822).

Almost surely, 2^12521643643 is an apocalyptic number.

12521643643 is a deficient number, since it is larger than the sum of its proper divisors (1).

12521643643 is an equidigital number, since it uses as much as digits as its factorization.

12521643643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 37.

The spelling of 12521643643 in words is "twelve billion, five hundred twenty-one million, six hundred forty-three thousand, six hundred forty-three".