1221706552 has 48 divisors (see below), whose sum is σ = 2568562920. Its totient is φ = 540259200.

The previous prime is 1221706543. The next prime is 1221706601. The reversal of 1221706552 is 2556071221.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 115402 + ... + 125542.

Almost surely, 2^1221706552 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221706552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1284281460).

1221706552 is an abundant number, since it is smaller than the sum of its proper divisors (1346856368).

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

1221706552 is a wasteful number, since it uses less digits than its factorization.

1221706552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10232 (or 10191 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 1221706552 is about 34952.9190769526. The cubic root of 1221706552 is about 1069.0277224883.

Adding to 1221706552 its reverse (2556071221), we get a palindrome (3777777773).

The spelling of 1221706552 in words is "one billion, two hundred twenty-one million, seven hundred six thousand, five hundred fifty-two".