1305250409 has 4 divisors (see below), whose sum is σ = 1305340740. Its totient is φ = 1305160080.

The previous prime is 1305250399. The next prime is 1305250411. The reversal of 1305250409 is 9040525031.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 752295184 + 552955225 = 27428^2 + 23515^2 .

It is a cyclic number.

It is not a de Polignac number, because 1305250409 - 2⁴ = 1305250393 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1305250469) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18074 + ... + 54195.

It is an arithmetic number, because the mean of its divisors is an integer number (326335185).

Almost surely, 2^1305250409 is an apocalyptic number.

It is an amenable number.

1305250409 is a deficient number, since it is larger than the sum of its proper divisors (90331).

1305250409 is an equidigital number, since it uses as much as digits as its factorization.

1305250409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90330.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 1305250409 is about 36128.2494593912. The cubic root of 1305250409 is about 1092.8602066169.

The spelling of 1305250409 in words is "one billion, three hundred five million, two hundred fifty thousand, four hundred nine".