21242525543 has 2 divisors, whose sum is σ = 21242525544. Its totient is φ = 21242525542.

The previous prime is 21242525519. The next prime is 21242525561. The reversal of 21242525543 is 34552524212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21242525543 - 2²⁶ = 21175416679 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21242525243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10621262771 + 10621262772.

It is an arithmetic number, because the mean of its divisors is an integer number (10621262772).

Almost surely, 2^21242525543 is an apocalyptic number.

21242525543 is a deficient number, since it is larger than the sum of its proper divisors (1).

21242525543 is an equidigital number, since it uses as much as digits as its factorization.

21242525543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96000, while the sum is 35.

The spelling of 21242525543 in words is "twenty-one billion, two hundred forty-two million, five hundred twenty-five thousand, five hundred forty-three".