21100100109 has 32 divisors (see below), whose sum is σ = 30915354624. Its totient is φ = 12694812480.

The previous prime is 21100100093. The next prime is 21100100143. The reversal of 21100100109 is 90100100112.

It is not a de Polignac number, because 21100100109 - 2⁴ = 21100100093 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 (21100100179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2741064 + ... + 2748750.

It is an arithmetic number, because the mean of its divisors is an integer number (966104832).

Almost surely, 2^21100100109 is an apocalyptic number.

It is an amenable number.

21100100109 is a deficient number, since it is larger than the sum of its proper divisors (9815254515).

21100100109 is a wasteful number, since it uses less digits than its factorization.

21100100109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8297.

The product of its (nonzero) digits is 18, while the sum is 15.

The spelling of 21100100109 in words is "twenty-one billion, one hundred million, one hundred thousand, one hundred nine".