21130121005 has 16 divisors (see below), whose sum is σ = 29685245184. Its totient is φ = 14135829120.

The previous prime is 21130120967. The next prime is 21130121011. The reversal of 21130121005 is 50012103112.

It is not a de Polignac number, because 21130121005 - 2⁷ = 21130120877 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21130121005.

It is a congruent number.

It is an unprimeable number.

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, 7360977 + ... + 7363846.

It is an arithmetic number, because the mean of its divisors is an integer number (1855327824).

Almost surely, 2^21130121005 is an apocalyptic number.

It is an amenable number.

21130121005 is a deficient number, since it is larger than the sum of its proper divisors (8555124179).

21130121005 is a wasteful number, since it uses less digits than its factorization.

21130121005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14724876.

The product of its (nonzero) digits is 60, while the sum is 16.

Adding to 21130121005 its reverse (50012103112), we get a palindrome (71142224117).

The spelling of 21130121005 in words is "twenty-one billion, one hundred thirty million, one hundred twenty-one thousand, five".