21432021121 has 12 divisors (see below), whose sum is σ = 24964627072. Its totient is φ = 18023677776.

The previous prime is 21432021097. The next prime is 21432021133. The reversal of 21432021121 is 12112023412.

It is not a de Polignac number, because 21432021121 - 2⁷ = 21432020993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21432061121) 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 11 ways as a sum of consecutive naturals, for example, 525321 + ... + 564646.

Almost surely, 2^21432021121 is an apocalyptic number.

It is an amenable number.

21432021121 is a deficient number, since it is larger than the sum of its proper divisors (3532605951).

21432021121 is an equidigital number, since it uses as much as digits as its factorization.

21432021121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1090080 (or 1090027 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 21432021121 its reverse (12112023412), we get a palindrome (33544044533).

The spelling of 21432021121 in words is "twenty-one billion, four hundred thirty-two million, twenty-one thousand, one hundred twenty-one".