1220867221 has 4 divisors (see below), whose sum is σ = 1395276832. Its totient is φ = 1046457612.

The previous prime is 1220867191. The next prime is 1220867227. The reversal of 1220867221 is 1227680221.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1227680221 = 229 ⋅5361049.

It is a cyclic number.

It is not a de Polignac number, because 1220867221 - 2¹⁵ = 1220834453 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 (1220867227) 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, 87204795 + ... + 87204808.

It is an arithmetic number, because the mean of its divisors is an integer number (348819208).

Almost surely, 2^1220867221 is an apocalyptic number.

It is an amenable number.

1220867221 is a deficient number, since it is larger than the sum of its proper divisors (174409611).

1220867221 is an equidigital number, since it uses as much as digits as its factorization.

1220867221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174409610.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 1220867221 is about 34940.9104203082. The cubic root of 1220867221 is about 1068.7828536302.

The spelling of 1220867221 in words is "one billion, two hundred twenty million, eight hundred sixty-seven thousand, two hundred twenty-one".