21254615121 has 16 divisors (see below), whose sum is σ = 28640589120. Its totient is φ = 14019566400.

The previous prime is 21254615111. The next prime is 21254615149. The reversal of 21254615121 is 12151645212.

It is not a de Polignac number, because 21254615121 - 2¹⁰ = 21254614097 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21254615111) 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 15 ways as a sum of consecutive naturals, for example, 182866 + ... + 275588.

It is an arithmetic number, because the mean of its divisors is an integer number (1790036820).

Almost surely, 2^21254615121 is an apocalyptic number.

It is an amenable number.

21254615121 is a deficient number, since it is larger than the sum of its proper divisors (7385973999).

21254615121 is a wasteful number, since it uses less digits than its factorization.

21254615121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93536.

The product of its digits is 4800, while the sum is 30.

The spelling of 21254615121 in words is "twenty-one billion, two hundred fifty-four million, six hundred fifteen thousand, one hundred twenty-one".