21240432002021 has 4 divisors (see below), whose sum is σ = 21321194101152. Its totient is φ = 21159669902892.

The previous prime is 21240432002017. The next prime is 21240432002077. The reversal of 21240432002021 is 12020023404212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21240432002021 - 2² = 21240432002017 is a prime.

It is a super-2 number, since 2×21240432002021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240432002221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40381049171 + ... + 40381049696.

It is an arithmetic number, because the mean of its divisors is an integer number (5330298525288).

Almost surely, 2^{21240432002021} is an apocalyptic number.

It is an amenable number.

21240432002021 is a deficient number, since it is larger than the sum of its proper divisors (80762099131).

21240432002021 is an equidigital number, since it uses as much as digits as its factorization.

21240432002021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80762099130.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21240432002021 its reverse (12020023404212), we get a palindrome (33260455406233).

The spelling of 21240432002021 in words is "twenty-one trillion, two hundred forty billion, four hundred thirty-two million, two thousand, twenty-one".