21220354523 has 2 divisors, whose sum is σ = 21220354524. Its totient is φ = 21220354522.

The previous prime is 21220354501. The next prime is 21220354537. The reversal of 21220354523 is 32545302212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21220354523 - 2¹² = 21220350427 is a prime.

It is not a weakly prime, because it can be changed into another prime (21220354583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610177261 + 10610177262.

It is an arithmetic number, because the mean of its divisors is an integer number (10610177262).

Almost surely, 2^21220354523 is an apocalyptic number.

21220354523 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220354523 is an equidigital number, since it uses as much as digits as its factorization.

21220354523 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14400, while the sum is 29.

Adding to 21220354523 its reverse (32545302212), we get a palindrome (53765656735).

The spelling of 21220354523 in words is "twenty-one billion, two hundred twenty million, three hundred fifty-four thousand, five hundred twenty-three".