21103451345523 has 32 divisors (see below), whose sum is σ = 29232339375616. Its totient is φ = 13531038812928.

The previous prime is 21103451345497. The next prime is 21103451345539. The reversal of 21103451345523 is 32554315430112.

It is not a de Polignac number, because 21103451345523 - 2⁸ = 21103451345267 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21103451345723) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4566615 + ... + 7941087.

It is an arithmetic number, because the mean of its divisors is an integer number (913510605488).

Almost surely, 2^{21103451345523} is an apocalyptic number.

21103451345523 is a deficient number, since it is larger than the sum of its proper divisors (8128888030093).

21103451345523 is a wasteful number, since it uses less digits than its factorization.

21103451345523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3375163.

The product of its (nonzero) digits is 216000, while the sum is 39.

Adding to 21103451345523 its reverse (32554315430112), we get a palindrome (53657766775635).

The spelling of 21103451345523 in words is "twenty-one trillion, one hundred three billion, four hundred fifty-one million, three hundred forty-five thousand, five hundred twenty-three".