21032120421 has 16 divisors (see below), whose sum is σ = 33555520320. Its totient is φ = 12942843120.

The previous prime is 21032120413. The next prime is 21032120423. The reversal of 21032120421 is 12402123012.

It is a happy number.

21032120421 is a `hidden beast` number, since 210 + 32 + 1 + 2 + 0 + 421 = 666.

It is not a de Polignac number, because 21032120421 - 2³ = 21032120413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21032120394 and 21032120403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21032120423) 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, 29959935 + ... + 29960636.

It is an arithmetic number, because the mean of its divisors is an integer number (2097220020).

Almost surely, 2^21032120421 is an apocalyptic number.

It is an amenable number.

21032120421 is a deficient number, since it is larger than the sum of its proper divisors (12523399899).

21032120421 is a wasteful number, since it uses less digits than its factorization.

21032120421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59920593 (or 59920587 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21032120421 its reverse (12402123012), we get a palindrome (33434243433).

The spelling of 21032120421 in words is "twenty-one billion, thirty-two million, one hundred twenty thousand, four hundred twenty-one".