21500121000126 has 16 divisors (see below), whose sum is σ = 43000763632128. Its totient is φ = 7166620061400.

The previous prime is 21500121000103. The next prime is 21500121000131. The reversal of 21500121000126 is 62100012100512.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21197820 + ... + 22188911.

It is an arithmetic number, because the mean of its divisors is an integer number (2687547727008).

Almost surely, 2^{21500121000126} is an apocalyptic number.

21500121000126 is an abundant number, since it is smaller than the sum of its proper divisors (21500642632002).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21500121000126 is a wasteful number, since it uses less digits than its factorization.

21500121000126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43469327.

The product of its (nonzero) digits is 240, while the sum is 21.

Adding to 21500121000126 its reverse (62100012100512), we get a palindrome (83600133100638).

The spelling of 21500121000126 in words is "twenty-one trillion, five hundred billion, one hundred twenty-one million, one hundred twenty-six", and thus it is an aban number.