21210413641 has 4 divisors (see below), whose sum is σ = 21210720784. Its totient is φ = 21210106500.

The previous prime is 21210413633. The next prime is 21210413687. The reversal of 21210413641 is 14631401212.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21210413641 - 2³ = 21210413633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21210413041) 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 3 ways as a sum of consecutive naturals, for example, 3706 + ... + 205996.

It is an arithmetic number, because the mean of its divisors is an integer number (5302680196).

Almost surely, 2^21210413641 is an apocalyptic number.

It is an amenable number.

21210413641 is a deficient number, since it is larger than the sum of its proper divisors (307143).

21210413641 is a wasteful number, since it uses less digits than its factorization.

21210413641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307142.

The product of its (nonzero) digits is 1152, while the sum is 25.

Adding to 21210413641 its reverse (14631401212), we get a palindrome (35841814853).

The spelling of 21210413641 in words is "twenty-one billion, two hundred ten million, four hundred thirteen thousand, six hundred forty-one".