1221033265 has 4 divisors (see below), whose sum is σ = 1465239924. Its totient is φ = 976826608.

The previous prime is 1221033199. The next prime is 1221033277. The reversal of 1221033265 is 5623301221.

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 797949504 + 423083761 = 28248^2 + 20569^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221033265 - 2²¹ = 1218936113 is a prime.

It is a Duffinian 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, 122103322 + ... + 122103331.

It is an arithmetic number, because the mean of its divisors is an integer number (366309981).

Almost surely, 2^1221033265 is an apocalyptic number.

It is an amenable number.

1221033265 is a deficient number, since it is larger than the sum of its proper divisors (244206659).

1221033265 is an equidigital number, since it uses as much as digits as its factorization.

1221033265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244206658.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 1221033265 is about 34943.2864081214. The cubic root of 1221033265 is about 1068.8313046909.

Adding to 1221033265 its reverse (5623301221), we get a palindrome (6844334486).

The spelling of 1221033265 in words is "one billion, two hundred twenty-one million, thirty-three thousand, two hundred sixty-five".