1215553 has 2 divisors, whose sum is σ = 1215554. Its totient is φ = 1215552.

The previous prime is 1215521. The next prime is 1215569. The reversal of 1215553 is 3555121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 627264 + 588289 = 792^2 + 767^2 .

It is an emirp because it is prime and its reverse (3555121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1215553 - 2⁵ = 1215521 is a prime.

It is not a weakly prime, because it can be changed into another prime (1215583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 607776 + 607777.

It is an arithmetic number, because the mean of its divisors is an integer number (607777).

2^1215553 is an apocalyptic number.

It is an amenable number.

1215553 is a deficient number, since it is larger than the sum of its proper divisors (1).

1215553 is an equidigital number, since it uses as much as digits as its factorization.

1215553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 750, while the sum is 22.

The square root of 1215553 is about 1102.5212016102. The cubic root of 1215553 is about 106.7229856668.

The spelling of 1215553 in words is "one million, two hundred fifteen thousand, five hundred fifty-three".