1221543 has 6 divisors (see below), whose sum is σ = 1764464. Its totient is φ = 814356.

The previous prime is 1221541. The next prime is 1221551. The reversal of 1221543 is 3451221.

1221543 is a `hidden beast` number, since 122 + 1 + 543 = 666.

It is not a de Polignac number, because 1221543 - 2¹ = 1221541 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 (1221541) 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 5 ways as a sum of consecutive naturals, for example, 67855 + ... + 67872.

2^1221543 is an apocalyptic number.

1221543 is a deficient number, since it is larger than the sum of its proper divisors (542921).

1221543 is a wasteful number, since it uses less digits than its factorization.

1221543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135733 (or 135730 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 1221543 is about 1105.2343642866. The cubic root of 1221543 is about 106.8980016154.

Adding to 1221543 its reverse (3451221), we get a palindrome (4672764).

It can be divided in two parts, 1221 and 543, that added together give a square (1764 = 42²).

The spelling of 1221543 in words is "one million, two hundred twenty-one thousand, five hundred forty-three".