1221222320 has 20 divisors (see below), whose sum is σ = 2839342080. Its totient is φ = 488488896.

The previous prime is 1221222287. The next prime is 1221222341. The reversal of 1221222320 is 232221221.

It is a tau number, because it is divible by the number of its divisors (20).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7632560 + ... + 7632719.

It is an arithmetic number, because the mean of its divisors is an integer number (141967104).

Almost surely, 2^1221222320 is an apocalyptic number.

1221222320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221222320 is an abundant number, since it is smaller than the sum of its proper divisors (1618119760).

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

1221222320 is a wasteful number, since it uses less digits than its factorization.

1221222320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15265292 (or 15265286 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 1221222320 is about 34945.9914725566. The cubic root of 1221222320 is about 1068.8864649338.

Adding to 1221222320 its reverse (232221221), we get a palindrome (1453443541).

The spelling of 1221222320 in words is "one billion, two hundred twenty-one million, two hundred twenty-two thousand, three hundred twenty".