1305640089 has 36 divisors (see below), whose sum is σ = 2089751664. Its totient is φ = 784746144.

The previous prime is 1305640019. The next prime is 1305640099. The reversal of 1305640089 is 9800465031.

1305640089 is a `hidden beast` number, since 1 + 3 + 0 + 5 + 640 + 0 + 8 + 9 = 666.

It is not a de Polignac number, because 1305640089 - 2⁸ = 1305639833 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1305640019) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 55422 + ... + 75384.

Almost surely, 2^1305640089 is an apocalyptic number.

It is an amenable number.

1305640089 is a deficient number, since it is larger than the sum of its proper divisors (784111575).

1305640089 is a wasteful number, since it uses less digits than its factorization.

1305640089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20038 (or 20022 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 1305640089 is about 36133.6420666392. The cubic root of 1305640089 is about 1092.9689529001.

The spelling of 1305640089 in words is "one billion, three hundred five million, six hundred forty thousand, eighty-nine".