1221661222 has 8 divisors (see below), whose sum is σ = 1841794416. Its totient is φ = 607729752.

The previous prime is 1221661219. The next prime is 1221661229. The reversal of 1221661222 is 2221661221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×1221661222² = 2984912282677066568, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221661229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1549938 + ... + 1550725.

It is an arithmetic number, because the mean of its divisors is an integer number (230224302).

Almost surely, 2^1221661222 is an apocalyptic number.

1221661222 is a deficient number, since it is larger than the sum of its proper divisors (620133194).

1221661222 is a wasteful number, since it uses less digits than its factorization.

1221661222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3100862.

The product of its digits is 1152, while the sum is 25.

The square root of 1221661222 is about 34952.2706272425. The cubic root of 1221661222 is about 1069.0145006482.

Subtracting 1221661222 from its reverse (2221661221), we obtain a palindrome (999999999).

The spelling of 1221661222 in words is "one billion, two hundred twenty-one million, six hundred sixty-one thousand, two hundred twenty-two".