21132430021 has 8 divisors (see below), whose sum is σ = 22962233600. Its totient is φ = 19374383520.

The previous prime is 21132430003. The next prime is 21132430031. The reversal of 21132430021 is 12003423112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21132430021 - 2¹⁹ = 21131905733 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21132430031) 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 7 ways as a sum of consecutive naturals, for example, 17938656 + ... + 17939833.

It is an arithmetic number, because the mean of its divisors is an integer number (2870279200).

Almost surely, 2^21132430021 is an apocalyptic number.

It is an amenable number.

21132430021 is a deficient number, since it is larger than the sum of its proper divisors (1829803579).

21132430021 is a wasteful number, since it uses less digits than its factorization.

21132430021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35878539.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21132430021 its reverse (12003423112), we get a palindrome (33135853133).

The spelling of 21132430021 in words is "twenty-one billion, one hundred thirty-two million, four hundred thirty thousand, twenty-one".