21523213441 has 2 divisors, whose sum is σ = 21523213442. Its totient is φ = 21523213440.

The previous prime is 21523213429. The next prime is 21523213457. The reversal of 21523213441 is 14431232512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19978409025 + 1544804416 = 141345^2 + 39304^2 .

It is a cyclic number.

It is not a de Polignac number, because 21523213441 - 2¹¹ = 21523211393 is a prime.

It is not a weakly prime, because it can be changed into another prime (21526213441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10761606720 + 10761606721.

It is an arithmetic number, because the mean of its divisors is an integer number (10761606721).

Almost surely, 2^21523213441 is an apocalyptic number.

It is an amenable number.

21523213441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21523213441 is an equidigital number, since it uses as much as digits as its factorization.

21523213441 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 28.

Adding to 21523213441 its reverse (14431232512), we get a palindrome (35954445953).

The spelling of 21523213441 in words is "twenty-one billion, five hundred twenty-three million, two hundred thirteen thousand, four hundred forty-one".