21100323021 has 8 divisors (see below), whose sum is σ = 28732354944. Its totient is φ = 13767586560.

The previous prime is 21100323017. The next prime is 21100323029. The reversal of 21100323021 is 12032300112.

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

It is not a de Polignac number, because 21100323021 - 2² = 21100323017 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100323029) 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, 74823700 + ... + 74823981.

It is an arithmetic number, because the mean of its divisors is an integer number (3591544368).

Almost surely, 2^21100323021 is an apocalyptic number.

It is an amenable number.

21100323021 is a deficient number, since it is larger than the sum of its proper divisors (7632031923).

21100323021 is a wasteful number, since it uses less digits than its factorization.

21100323021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149647731.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21100323021 its reverse (12032300112), we get a palindrome (33132623133).

The spelling of 21100323021 in words is "twenty-one billion, one hundred million, three hundred twenty-three thousand, twenty-one".