21210213241 has 4 divisors (see below), whose sum is σ = 24240243712. Its totient is φ = 18180182772.

The previous prime is 21210213179. The next prime is 21210213263. The reversal of 21210213241 is 14231201212.

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 21210213241 - 2¹⁹ = 21209688953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21210213281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1515015225 + ... + 1515015238.

It is an arithmetic number, because the mean of its divisors is an integer number (6060060928).

Almost surely, 2^21210213241 is an apocalyptic number.

It is an amenable number.

21210213241 is a deficient number, since it is larger than the sum of its proper divisors (3030030471).

21210213241 is an equidigital number, since it uses as much as digits as its factorization.

21210213241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3030030470.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 21210213241 its reverse (14231201212), we get a palindrome (35441414453).

The spelling of 21210213241 in words is "twenty-one billion, two hundred ten million, two hundred thirteen thousand, two hundred forty-one".