75909809 has 4 divisors (see below), whose sum is σ = 75958260. Its totient is φ = 75861360.

The previous prime is 75909797. The next prime is 75909817. The reversal of 75909809 is 90890957.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 29669809 + 46240000 = 5447^2 + 6800^2 .

It is a cyclic number.

It is not a de Polignac number, because 75909809 - 2⁸ = 75909553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (75909839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21794 + ... + 25035.

It is an arithmetic number, because the mean of its divisors is an integer number (18989565).

Almost surely, 2^75909809 is an apocalyptic number.

It is an amenable number.

75909809 is a deficient number, since it is larger than the sum of its proper divisors (48451).

75909809 is a wasteful number, since it uses less digits than its factorization.

75909809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48450.

The product of its (nonzero) digits is 204120, while the sum is 47.

The square root of 75909809 is about 8712.6235428831. The cubic root of 75909809 is about 423.4147336943.

The spelling of 75909809 in words is "seventy-five million, nine hundred nine thousand, eight hundred nine".