21100010001 has 48 divisors (see below), whose sum is σ = 34200612864. Its totient is φ = 11526018336.

The previous prime is 21100009981. The next prime is 21100010027. The reversal of 21100010001 is 10001000112.

It is not a de Polignac number, because 21100010001 - 2¹⁵ = 21099977233 is a prime.

21100010001 is a modest number, since divided by 10001 gives 211 as remainder.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21100010081) 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, 261576 + ... + 332598.

It is an arithmetic number, because the mean of its divisors is an integer number (712512768).

Almost surely, 2^21100010001 is an apocalyptic number.

21100010001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21100010001 is a deficient number, since it is larger than the sum of its proper divisors (13100602863).

21100010001 is a wasteful number, since it uses less digits than its factorization.

21100010001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71130 (or 71123 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 6.

Adding to 21100010001 its reverse (10001000112), we get a palindrome (31101010113).

The spelling of 21100010001 in words is "twenty-one billion, one hundred million, ten thousand, one".