21013024021 has 16 divisors (see below), whose sum is σ = 23493730176. Its totient is φ = 18627840000.

The previous prime is 21013024007. The next prime is 21013024031. The reversal of 21013024021 is 12042031012.

It is a de Polignac number, because none of the positive numbers 2^k-21013024021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21013023986 and 21013024004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013024031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1032181 + ... + 1052341.

It is an arithmetic number, because the mean of its divisors is an integer number (1468358136).

Almost surely, 2^21013024021 is an apocalyptic number.

It is an amenable number.

21013024021 is a deficient number, since it is larger than the sum of its proper divisors (2480706155).

21013024021 is a wasteful number, since it uses less digits than its factorization.

21013024021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22524.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21013024021 its reverse (12042031012), we get a palindrome (33055055033).

The spelling of 21013024021 in words is "twenty-one billion, thirteen million, twenty-four thousand, twenty-one".