21012200109 has 12 divisors (see below), whose sum is σ = 30803955936. Its totient is φ = 13799056392.

The previous prime is 21012200101. The next prime is 21012200119. The reversal of 21012200109 is 90100221012.

It is not a de Polignac number, because 21012200109 - 2³ = 21012200101 is a prime.

It is a super-2 number, since 2×21012200109² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21012200091 and 21012200100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012200101) 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 11 ways as a sum of consecutive naturals, for example, 17422449 + ... + 17423654.

It is an arithmetic number, because the mean of its divisors is an integer number (2566996328).

Almost surely, 2^21012200109 is an apocalyptic number.

It is an amenable number.

21012200109 is a deficient number, since it is larger than the sum of its proper divisors (9791755827).

21012200109 is a wasteful number, since it uses less digits than its factorization.

21012200109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34846176 (or 34846173 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The spelling of 21012200109 in words is "twenty-one billion, twelve million, two hundred thousand, one hundred nine".