1221262559 has 12 divisors (see below), whose sum is σ = 1343225520. Its totient is φ = 1109539200.

The previous prime is 1221262543. The next prime is 1221262561. The reversal of 1221262559 is 9552621221.

It is not a de Polignac number, because 1221262559 - 2⁴ = 1221262543 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 (1221262459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 366302 + ... + 369620.

It is an arithmetic number, because the mean of its divisors is an integer number (111935460).

Almost surely, 2^1221262559 is an apocalyptic number.

1221262559 is a deficient number, since it is larger than the sum of its proper divisors (121962961).

1221262559 is a wasteful number, since it uses less digits than its factorization.

1221262559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6382 (or 6371 counting only the distinct ones).

The product of its digits is 21600, while the sum is 35.

The square root of 1221262559 is about 34946.5671990827. The cubic root of 1221262559 is about 1068.8982046608.

The spelling of 1221262559 in words is "one billion, two hundred twenty-one million, two hundred sixty-two thousand, five hundred fifty-nine".