21424711521 has 16 divisors (see below), whose sum is σ = 28879464960. Its totient is φ = 14127079680.

The previous prime is 21424711507. The next prime is 21424711523. The reversal of 21424711521 is 12511742412.

It is not a de Polignac number, because 21424711521 - 2⁶ = 21424711457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21424711523) 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, 96411 + ... + 228351.

It is an arithmetic number, because the mean of its divisors is an integer number (1804966560).

Almost surely, 2^21424711521 is an apocalyptic number.

It is an amenable number.

21424711521 is a deficient number, since it is larger than the sum of its proper divisors (7454753439).

21424711521 is a wasteful number, since it uses less digits than its factorization.

21424711521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132536.

The product of its digits is 4480, while the sum is 30.

The spelling of 21424711521 in words is "twenty-one billion, four hundred twenty-four million, seven hundred eleven thousand, five hundred twenty-one".