21500053250121 has 16 divisors (see below), whose sum is σ = 33725573726400. Its totient is φ = 13490229489984.

The previous prime is 21500053250119. The next prime is 21500053250129. The reversal of 21500053250121 is 12105235000512.

21500053250121 is a `hidden beast` number, since 2 + 1 + 5 + 0 + 0 + 0 + 532 + 5 + 0 + 121 = 666.

It is not a de Polignac number, because 21500053250121 - 2¹ = 21500053250119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21500053250129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23420536851 + ... + 23420537768.

It is an arithmetic number, because the mean of its divisors is an integer number (2107848357900).

Almost surely, 2^{21500053250121} is an apocalyptic number.

It is an amenable number.

21500053250121 is a deficient number, since it is larger than the sum of its proper divisors (12225520476279).

21500053250121 is a wasteful number, since it uses less digits than its factorization.

21500053250121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46841074645 (or 46841074639 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

Adding to 21500053250121 its reverse (12105235000512), we get a palindrome (33605288250633).

The spelling of 21500053250121 in words is "twenty-one trillion, five hundred billion, fifty-three million, two hundred fifty thousand, one hundred twenty-one".