21242236429 has 2 divisors, whose sum is σ = 21242236430. Its totient is φ = 21242236428.

The previous prime is 21242236403. The next prime is 21242236441. The reversal of 21242236429 is 92463224212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14018086404 + 7224150025 = 118398^2 + 84995^2 .

It is a cyclic number.

It is not a de Polignac number, because 21242236429 - 2²⁹ = 20705365517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21242236529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10621118214 + 10621118215.

It is an arithmetic number, because the mean of its divisors is an integer number (10621118215).

Almost surely, 2^21242236429 is an apocalyptic number.

It is an amenable number.

21242236429 is a deficient number, since it is larger than the sum of its proper divisors (1).

21242236429 is an equidigital number, since it uses as much as digits as its factorization.

21242236429 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 37.

The spelling of 21242236429 in words is "twenty-one billion, two hundred forty-two million, two hundred thirty-six thousand, four hundred twenty-nine".