1245681 has 12 divisors (see below), whose sum is σ = 1829620. Its totient is φ = 816480.

The previous prime is 1245649. The next prime is 1245683. The reversal of 1245681 is 1865421.

It can be written as a sum of positive squares in 2 ways, for example, as 46656 + 1199025 = 216^2 + 1095^2 .

It is not a de Polignac number, because 1245681 - 2⁵ = 1245649 is a prime.

It is a super-2 number, since 2×1245681² = 3103442307522, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1245683) 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, 586 + ... + 1683.

2^1245681 is an apocalyptic number.

It is an amenable number.

1245681 is a deficient number, since it is larger than the sum of its proper divisors (583939).

1245681 is a wasteful number, since it uses less digits than its factorization.

1245681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2336 (or 2333 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 1245681 is about 1116.1008018992. The cubic root of 1245681 is about 107.5975246226.

The spelling of 1245681 in words is "one million, two hundred forty-five thousand, six hundred eighty-one".