1245199805 has 18 divisors (see below), whose sum is σ = 1533977406. Its totient is φ = 970342128.

The previous prime is 1245199793. The next prime is 1245199819. The reversal of 1245199805 is 5089915421.

It can be written as a sum of positive squares in only one way, i.e., 996159844 + 249039961 = 31562^2 + 15781^2 .

It is not a de Polignac number, because 1245199805 - 2⁶ = 1245199741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3392732 + ... + 3393098.

It is an arithmetic number, because the mean of its divisors is an integer number (85220967).

Almost surely, 2^1245199805 is an apocalyptic number.

It is an amenable number.

1245199805 is a deficient number, since it is larger than the sum of its proper divisors (288777601).

1245199805 is an frugal number, since it uses more digits than its factorization.

1245199805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825 (or 415 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 44.

The square root of 1245199805 is about 35287.3887529242. The cubic root of 1245199805 is about 1075.8366819674.

The spelling of 1245199805 in words is "one billion, two hundred forty-five million, one hundred ninety-nine thousand, eight hundred five".