51905909 has 8 divisors (see below), whose sum is σ = 57145440. Its totient is φ = 46753200.

The previous prime is 51905881. The next prime is 51905933. The reversal of 51905909 is 90950915.

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 51905909 - 2⁸ = 51905653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51905939) 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 7 ways as a sum of consecutive naturals, for example, 20447 + ... + 22844.

It is an arithmetic number, because the mean of its divisors is an integer number (7143180).

Almost surely, 2^51905909 is an apocalyptic number.

It is an amenable number.

51905909 is a deficient number, since it is larger than the sum of its proper divisors (5239531).

51905909 is a wasteful number, since it uses less digits than its factorization.

51905909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43411.

The product of its (nonzero) digits is 18225, while the sum is 38.

The square root of 51905909 is about 7204.5755600174. The cubic root of 51905909 is about 373.0258543079.

The spelling of 51905909 in words is "fifty-one million, nine hundred five thousand, nine hundred nine".