21132321641 has 4 divisors (see below), whose sum is σ = 21140869332. Its totient is φ = 21123773952.

The previous prime is 21132321611. The next prime is 21132321647. The reversal of 21132321641 is 14612323112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13529179225 + 7603142416 = 116315^2 + 87196^2 .

It is a cyclic number.

It is not a de Polignac number, because 21132321641 - 2¹⁸ = 21132059497 is a prime.

It is a super-3 number, since 3×21132321641³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21132321641.

It is not an unprimeable number, because it can be changed into a prime (21132321647) 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 3 ways as a sum of consecutive naturals, for example, 4270136 + ... + 4275081.

It is an arithmetic number, because the mean of its divisors is an integer number (5285217333).

Almost surely, 2^21132321641 is an apocalyptic number.

It is an amenable number.

21132321641 is a deficient number, since it is larger than the sum of its proper divisors (8547691).

21132321641 is an equidigital number, since it uses as much as digits as its factorization.

21132321641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8547690.

The product of its digits is 1728, while the sum is 26.

Adding to 21132321641 its reverse (14612323112), we get a palindrome (35744644753).

The spelling of 21132321641 in words is "twenty-one billion, one hundred thirty-two million, three hundred twenty-one thousand, six hundred forty-one".