30556221221 has 4 divisors (see below), whose sum is σ = 30556741344. Its totient is φ = 30555701100.

The previous prime is 30556221203. The next prime is 30556221233. The reversal of 30556221221 is 12212265503.

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 a de Polignac number, because none of the positive numbers 2^k-30556221221 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 (30556221251) 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, 158795 + ... + 293816.

It is an arithmetic number, because the mean of its divisors is an integer number (7639185336).

Almost surely, 2^30556221221 is an apocalyptic number.

It is an amenable number.

30556221221 is a deficient number, since it is larger than the sum of its proper divisors (520123).

30556221221 is an equidigital number, since it uses as much as digits as its factorization.

30556221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520122.

The product of its (nonzero) digits is 7200, while the sum is 29.

Adding to 30556221221 its reverse (12212265503), we get a palindrome (42768486724).

The spelling of 30556221221 in words is "thirty billion, five hundred fifty-six million, two hundred twenty-one thousand, two hundred twenty-one".