221220312030 has 32 divisors (see below), whose sum is σ = 589920832800. Its totient is φ = 58992083136.

The previous prime is 221220311899. The next prime is 221220312037. The reversal of 221220312030 is 30213022122.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221220311994 and 221220312012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220312037) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 409666975 + ... + 409667514.

It is an arithmetic number, because the mean of its divisors is an integer number (18435026025).

Almost surely, 2^221220312030 is an apocalyptic number.

221220312030 is an abundant number, since it is smaller than the sum of its proper divisors (368700520770).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221220312030 is a wasteful number, since it uses less digits than its factorization.

221220312030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819334505 (or 819334499 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 221220312030 its reverse (30213022122), we get a palindrome (251433334152).

The spelling of 221220312030 in words is "two hundred twenty-one billion, two hundred twenty million, three hundred twelve thousand, thirty".