1221265 has 4 divisors (see below), whose sum is σ = 1465524. Its totient is φ = 977008.

The previous prime is 1221251. The next prime is 1221289. The reversal of 1221265 is 5621221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 253009 + 968256 = 503^2 + 984^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221265 is a prime.

It is a Duffinian number.

1221265 is a lucky number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122122 + ... + 122131.

It is an arithmetic number, because the mean of its divisors is an integer number (366381).

2^1221265 is an apocalyptic number.

It is an amenable number.

1221265 is a deficient number, since it is larger than the sum of its proper divisors (244259).

1221265 is an equidigital number, since it uses as much as digits as its factorization.

1221265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244258.

The product of its digits is 240, while the sum is 19.

The square root of 1221265 is about 1105.1085919492. The cubic root of 1221265 is about 106.8898916814.

Subtracting from 1221265 its product of digits (240), we obtain a square (1221025 = 1105²).

Adding to 1221265 its reverse (5621221), we get a palindrome (6842486).

The spelling of 1221265 in words is "one million, two hundred twenty-one thousand, two hundred sixty-five".