1245665 has 4 divisors (see below), whose sum is σ = 1494804. Its totient is φ = 996528.

The previous prime is 1245649. The next prime is 1245683. The reversal of 1245665 is 5665421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5665421 = 41 ⋅138181.

It can be written as a sum of positive squares in 2 ways, for example, as 824464 + 421201 = 908^2 + 649^2 .

It is a cyclic number.

It is not a de Polignac number, because 1245665 - 2⁴ = 1245649 is a prime.

It is a Duffinian number.

It is a Curzon 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, 124562 + ... + 124571.

It is an arithmetic number, because the mean of its divisors is an integer number (373701).

2^1245665 is an apocalyptic number.

It is an amenable number.

1245665 is a deficient number, since it is larger than the sum of its proper divisors (249139).

1245665 is an equidigital number, since it uses as much as digits as its factorization.

1245665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249138.

The product of its digits is 7200, while the sum is 29.

The square root of 1245665 is about 1116.0936340648. The cubic root of 1245665 is about 107.5970639461.

It can be divided in two parts, 12456 and 65, that added together give a palindrome (12521).

The spelling of 1245665 in words is "one million, two hundred forty-five thousand, six hundred sixty-five".