1220220221 has 4 divisors (see below), whose sum is σ = 1331149344. Its totient is φ = 1109291100.

The previous prime is 1220220193. The next prime is 1220220227.

1220220221 is nontrivially palindromic in base 10.

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-1220220221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220220196 and 1220220205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220220227) 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, 55464545 + ... + 55464566.

It is an arithmetic number, because the mean of its divisors is an integer number (332787336).

Almost surely, 2^1220220221 is an apocalyptic number.

1220220221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1220220221 is a deficient number, since it is larger than the sum of its proper divisors (110929123).

1220220221 is a wasteful number, since it uses less digits than its factorization.

1220220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110929122.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 1220220221 is about 34931.6507053417. The cubic root of 1220220221 is about 1068.5940193643.

It can be divided in two parts, 12202 and 20221, that added together give a palindrome (32423).

The spelling of 1220220221 in words is "one billion, two hundred twenty million, two hundred twenty thousand, two hundred twenty-one".