21030413221 has 4 divisors (see below), whose sum is σ = 21030778944. Its totient is φ = 21030047500.

The previous prime is 21030413203. The next prime is 21030413231. The reversal of 21030413221 is 12231403012.

It is a happy number.

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 21030413221 - 2⁹ = 21030412709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030413231) 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, 75655 + ... + 218596.

It is an arithmetic number, because the mean of its divisors is an integer number (5257694736).

Almost surely, 2^21030413221 is an apocalyptic number.

It is an amenable number.

21030413221 is a deficient number, since it is larger than the sum of its proper divisors (365723).

21030413221 is an equidigital number, since it uses as much as digits as its factorization.

21030413221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365722.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21030413221 its reverse (12231403012), we get a palindrome (33261816233).

The spelling of 21030413221 in words is "twenty-one billion, thirty million, four hundred thirteen thousand, two hundred twenty-one".