51440065 has 8 divisors (see below), whose sum is σ = 61785000. Its totient is φ = 41114112.

The previous prime is 51440047. The next prime is 51440071. The reversal of 51440065 is 56004415.

It can be written as a sum of positive squares in 4 ways, for example, as 5837056 + 45603009 = 2416^2 + 6753^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51440065 - 2¹³ = 51431873 is a prime.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 2127 + ... + 10363.

It is an arithmetic number, because the mean of its divisors is an integer number (7723125).

Almost surely, 2^51440065 is an apocalyptic number.

It is an amenable number.

51440065 is a deficient number, since it is larger than the sum of its proper divisors (10344935).

51440065 is a wasteful number, since it uses less digits than its factorization.

51440065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9491.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 51440065 is about 7172.1729622200. The cubic root of 51440065 is about 371.9065577343.

The spelling of 51440065 in words is "fifty-one million, four hundred forty thousand, sixty-five".