21101001988453 has 2 divisors, whose sum is σ = 21101001988454. Its totient is φ = 21101001988452.

The previous prime is 21101001988393. The next prime is 21101001988477. The reversal of 21101001988453 is 35488910010112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20321865648484 + 779136339969 = 4507978^2 + 882687^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101001988453 - 2²⁹ = 21100465117541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21101001988483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550500994226 + 10550500994227.

It is an arithmetic number, because the mean of its divisors is an integer number (10550500994227).

Almost surely, 2^{21101001988453} is an apocalyptic number.

It is an amenable number.

21101001988453 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101001988453 is an equidigital number, since it uses as much as digits as its factorization.

21101001988453 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69120, while the sum is 43.

Adding to 21101001988453 its reverse (35488910010112), we get a palindrome (56589911998565).

The spelling of 21101001988453 in words is "twenty-one trillion, one hundred one billion, one million, nine hundred eighty-eight thousand, four hundred fifty-three".