1265665 has 4 divisors (see below), whose sum is σ = 1518804. Its totient is φ = 1012528.

The previous prime is 1265657. The next prime is 1265681. The reversal of 1265665 is 5665621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5665621 = 13 ⋅435817.

It can be written as a sum of positive squares in 2 ways, for example, as 638401 + 627264 = 799^2 + 792^2 .

It is a cyclic number.

It is not a de Polignac number, because 1265665 - 2³ = 1265657 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, 126562 + ... + 126571.

It is an arithmetic number, because the mean of its divisors is an integer number (379701).

It is a Proth number, since it is equal to 309 ⋅ 2¹² + 1 and 309 < 2¹².

2^1265665 is an apocalyptic number.

It is an amenable number.

1265665 is a deficient number, since it is larger than the sum of its proper divisors (253139).

1265665 is an equidigital number, since it uses as much as digits as its factorization.

1265665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253138.

The product of its digits is 10800, while the sum is 31.

The square root of 1265665 is about 1125.0177776373. The cubic root of 1265665 is about 108.1698573163.

It can be divided in two parts, 12656 and 65, that added together give a palindrome (12721).

The spelling of 1265665 in words is "one million, two hundred sixty-five thousand, six hundred sixty-five".