51143809 has 4 divisors (see below), whose sum is σ = 51175216. Its totient is φ = 51112404.

The previous prime is 51143797. The next prime is 51143821. The reversal of 51143809 is 90834115.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (51143797) and next prime (51143821).

It is a cyclic number.

It is not a de Polignac number, because 51143809 - 2⁵ = 51143777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51143909) 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, 13119 + ... + 16564.

It is an arithmetic number, because the mean of its divisors is an integer number (12793804).

Almost surely, 2^51143809 is an apocalyptic number.

It is an amenable number.

51143809 is a deficient number, since it is larger than the sum of its proper divisors (31407).

51143809 is a wasteful number, since it uses less digits than its factorization.

51143809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31406.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 51143809 is about 7151.4899846116. The cubic root of 51143809 is about 371.1912155486.

The spelling of 51143809 in words is "fifty-one million, one hundred forty-three thousand, eight hundred nine".