21525504241 has 2 divisors, whose sum is σ = 21525504242. Its totient is φ = 21525504240.

The previous prime is 21525504239. The next prime is 21525504251. The reversal of 21525504241 is 14240552512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20713254241 + 812250000 = 143921^2 + 28500^2 .

It is a cyclic number.

It is not a de Polignac number, because 21525504241 - 2¹ = 21525504239 is a prime.

Together with 21525504239, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21525504211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10762752120 + 10762752121.

It is an arithmetic number, because the mean of its divisors is an integer number (10762752121).

Almost surely, 2^21525504241 is an apocalyptic number.

It is an amenable number.

21525504241 is a deficient number, since it is larger than the sum of its proper divisors (1).

21525504241 is an equidigital number, since it uses as much as digits as its factorization.

21525504241 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16000, while the sum is 31.

The spelling of 21525504241 in words is "twenty-one billion, five hundred twenty-five million, five hundred four thousand, two hundred forty-one".