21523053105 has 48 divisors (see below), whose sum is σ = 40022498880. Its totient is φ = 11083117248.

The previous prime is 21523053089. The next prime is 21523053107. The reversal of 21523053105 is 50135032512.

It is a happy number.

It is not a de Polignac number, because 21523053105 - 2⁴ = 21523053089 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21523053107) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 270187 + ... + 340656.

It is an arithmetic number, because the mean of its divisors is an integer number (833802060).

Almost surely, 2^21523053105 is an apocalyptic number.

It is an amenable number.

21523053105 is a deficient number, since it is larger than the sum of its proper divisors (18499445775).

21523053105 is an equidigital number, since it uses as much as digits as its factorization.

21523053105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610892 (or 610880 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

Adding to 21523053105 its reverse (50135032512), we get a palindrome (71658085617).

The spelling of 21523053105 in words is "twenty-one billion, five hundred twenty-three million, fifty-three thousand, one hundred five".