21132040021 has 2 divisors, whose sum is σ = 21132040022. Its totient is φ = 21132040020.

The previous prime is 21132040003. The next prime is 21132040067. The reversal of 21132040021 is 12004023112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14133880996 + 6998159025 = 118886^2 + 83655^2 .

It is a cyclic number.

It is not a de Polignac number, because 21132040021 - 2¹⁹ = 21131515733 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21132039977 and 21132040004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21132040001) 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 as a sum of consecutive naturals, namely, 10566020010 + 10566020011.

It is an arithmetic number, because the mean of its divisors is an integer number (10566020011).

Almost surely, 2^21132040021 is an apocalyptic number.

It is an amenable number.

21132040021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21132040021 is an equidigital number, since it uses as much as digits as its factorization.

21132040021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21132040021 its reverse (12004023112), we get a palindrome (33136063133).

The spelling of 21132040021 in words is "twenty-one billion, one hundred thirty-two million, forty thousand, twenty-one".