1221573 has 4 divisors (see below), whose sum is σ = 1628768. Its totient is φ = 814380.

The previous prime is 1221559. The next prime is 1221589. The reversal of 1221573 is 3751221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3751221 = 3 ⋅1250407.

It is not a de Polignac number, because 1221573 - 2⁴ = 1221557 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203593 + ... + 203598.

It is an arithmetic number, because the mean of its divisors is an integer number (407192).

2^1221573 is an apocalyptic number.

It is an amenable number.

1221573 is a deficient number, since it is larger than the sum of its proper divisors (407195).

1221573 is an equidigital number, since it uses as much as digits as its factorization.

1221573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407194.

The product of its digits is 420, while the sum is 21.

The square root of 1221573 is about 1105.2479359854. The cubic root of 1221573 is about 106.8988767145.

Adding to 1221573 its reverse (3751221), we get a palindrome (4972794).

The spelling of 1221573 in words is "one million, two hundred twenty-one thousand, five hundred seventy-three".