21100105523 has 8 divisors (see below), whose sum is σ = 24131654400. Its totient is φ = 18072868680.

The previous prime is 21100105487. The next prime is 21100105529. The reversal of 21100105523 is 32550100112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21100105523 - 2¹² = 21100101427 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21100105495 and 21100105504.

It is not an unprimeable number, because it can be changed into a prime (21100105529) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1067513 + ... + 1087098.

It is an arithmetic number, because the mean of its divisors is an integer number (3016456800).

Almost surely, 2^21100105523 is an apocalyptic number.

21100105523 is a deficient number, since it is larger than the sum of its proper divisors (3031548877).

21100105523 is a wasteful number, since it uses less digits than its factorization.

21100105523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2156017.

The product of its (nonzero) digits is 300, while the sum is 20.

Adding to 21100105523 its reverse (32550100112), we get a palindrome (53650205635).

The spelling of 21100105523 in words is "twenty-one billion, one hundred million, one hundred five thousand, five hundred twenty-three".