1220212220221 has 4 divisors (see below), whose sum is σ = 1273264925472. Its totient is φ = 1167159514972.

The previous prime is 1220212220209. The next prime is 1220212220237. The reversal of 1220212220221 is 1220222120221.

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-1220212220221 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 (1220212220261) 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, 26526352591 + ... + 26526352636.

It is an arithmetic number, because the mean of its divisors is an integer number (318316231368).

Almost surely, 2^{1220212220221} is an apocalyptic number.

It is an amenable number.

1220212220221 is a deficient number, since it is larger than the sum of its proper divisors (53052705251).

1220212220221 is an equidigital number, since it uses as much as digits as its factorization.

1220212220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53052705250.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 1220212220221 its reverse (1220222120221), we get a palindrome (2440434340442).

The spelling of 1220212220221 in words is "one trillion, two hundred twenty billion, two hundred twelve million, two hundred twenty thousand, two hundred twenty-one".