21432345121 has 32 divisors (see below), whose sum is σ = 24206376960. Its totient is φ = 18809179200.

The previous prime is 21432345091. The next prime is 21432345131. The reversal of 21432345121 is 12154323412.

It is a cyclic number.

It is not a de Polignac number, because 21432345121 - 2¹⁷ = 21432214049 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21432345121.

It is not an unprimeable number, because it can be changed into a prime (21432345131) 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 31 ways as a sum of consecutive naturals, for example, 12540015 + ... + 12541723.

It is an arithmetic number, because the mean of its divisors is an integer number (756449280).

Almost surely, 2^21432345121 is an apocalyptic number.

It is an amenable number.

21432345121 is a deficient number, since it is larger than the sum of its proper divisors (2774031839).

21432345121 is a wasteful number, since it uses less digits than its factorization.

21432345121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2085.

The product of its digits is 5760, while the sum is 28.

Adding to 21432345121 its reverse (12154323412), we get a palindrome (33586668533).

The spelling of 21432345121 in words is "twenty-one billion, four hundred thirty-two million, three hundred forty-five thousand, one hundred twenty-one".