21100012101 has 24 divisors (see below), whose sum is σ = 35045474880. Its totient is φ = 11983173696.

The previous prime is 21100012093. The next prime is 21100012103. The reversal of 21100012101 is 10121000112.

It is a happy number.

It is not a de Polignac number, because 21100012101 - 2³ = 21100012093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100012103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1017096 + ... + 1037633.

It is an arithmetic number, because the mean of its divisors is an integer number (1460228120).

Almost surely, 2^21100012101 is an apocalyptic number.

21100012101 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21100012101 is a deficient number, since it is larger than the sum of its proper divisors (13945462779).

21100012101 is a wasteful number, since it uses less digits than its factorization.

21100012101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2054905 (or 2054902 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21100012101 its reverse (10121000112), we get a palindrome (31221012213).

The spelling of 21100012101 in words is "twenty-one billion, one hundred million, twelve thousand, one hundred one".