1221577 has 12 divisors (see below), whose sum is σ = 1444480.
Its totient is φ = 1011816.
The previous prime is 1221559. The next prime is 1221589. The reversal of 1221577 is 7751221.
Adding to 1221577 its reverse (7751221), we get a palindrome (8972798).
It is a happy number.
It is not a de Polignac number, because 1221577 - 27 = 1221449 is a prime.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (1221527) by changing a digit.
It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15424 + ... + 15502.
21221577 is an apocalyptic number.
1221577 is the 553-rd decagonal number.
It is an amenable number.
1221577 is a deficient number, since it is larger than the sum of its proper divisors (222903).
1221577 is an frugal number, since it uses more digits than its factorization.
1221577 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 180 (or 133 counting only the distinct ones).
The product of its digits is 980, while the sum is 25.
The square root of 1221577 is about 1105.2497455327.
The cubic root of 1221577 is about 106.8989933933.
The spelling of 1221577 in words is "one million, two hundred twenty-one thousand, five hundred seventy-seven".