1455557221 has 4 divisors (see below), whose sum is σ = 1541178252. Its totient is φ = 1369936192.

The previous prime is 1455557219. The next prime is 1455557249. The reversal of 1455557221 is 1227555541.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1227555541 = 47 ⋅26118203.

It can be written as a sum of positive squares in 2 ways, for example, as 1262736225 + 192820996 = 35535^2 + 13886^2 .

It is a cyclic number.

It is not a de Polignac number, because 1455557221 - 2¹ = 1455557219 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 (1455557281) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 42810490 + ... + 42810523.

It is an arithmetic number, because the mean of its divisors is an integer number (385294563).

Almost surely, 2^1455557221 is an apocalyptic number.

It is an amenable number.

1455557221 is a deficient number, since it is larger than the sum of its proper divisors (85621031).

1455557221 is an equidigital number, since it uses as much as digits as its factorization.

1455557221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85621030.

The product of its digits is 70000, while the sum is 37.

The square root of 1455557221 is about 38151.7656341093. The cubic root of 1455557221 is about 1133.2953175157.

The spelling of 1455557221 in words is "one billion, four hundred fifty-five million, five hundred fifty-seven thousand, two hundred twenty-one".