21603572429 has 2 divisors, whose sum is σ = 21603572430. Its totient is φ = 21603572428.

The previous prime is 21603572399. The next prime is 21603572437. The reversal of 21603572429 is 92427530612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18878210404 + 2725362025 = 137398^2 + 52205^2 .

It is a cyclic number.

It is not a de Polignac number, because 21603572429 - 2¹² = 21603568333 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21603572449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10801786214 + 10801786215.

It is an arithmetic number, because the mean of its divisors is an integer number (10801786215).

Almost surely, 2^21603572429 is an apocalyptic number.

It is an amenable number.

21603572429 is a deficient number, since it is larger than the sum of its proper divisors (1).

21603572429 is an equidigital number, since it uses as much as digits as its factorization.

21603572429 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 181440, while the sum is 41.

The spelling of 21603572429 in words is "twenty-one billion, six hundred three million, five hundred seventy-two thousand, four hundred twenty-nine".