21100223210172 has 96 divisors (see below), whose sum is σ = 51140154510144. Its totient is φ = 6765931929600.

The previous prime is 21100223210161. The next prime is 21100223210173. The reversal of 21100223210172 is 27101232200112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100223210173) 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, 128533168 + ... + 128697224.

It is an arithmetic number, because the mean of its divisors is an integer number (532709942814).

Almost surely, 2^{21100223210172} is an apocalyptic number.

It is an amenable number.

21100223210172 is an abundant number, since it is smaller than the sum of its proper divisors (30039931299972).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21100223210172 is a wasteful number, since it uses less digits than its factorization.

21100223210172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167759 (or 167757 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

Adding to 21100223210172 its reverse (27101232200112), we get a palindrome (48201455410284).

The spelling of 21100223210172 in words is "twenty-one trillion, one hundred billion, two hundred twenty-three million, two hundred ten thousand, one hundred seventy-two".