51005509 has 8 divisors (see below), whose sum is σ = 53146368. Its totient is φ = 48895680.

The previous prime is 51005503. The next prime is 51005533. The reversal of 51005509 is 90550015.

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

It is not a de Polignac number, because 51005509 - 2²¹ = 48908357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51005503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4372 + ... + 11005.

It is an arithmetic number, because the mean of its divisors is an integer number (6643296).

Almost surely, 2^51005509 is an apocalyptic number.

It is an amenable number.

51005509 is a deficient number, since it is larger than the sum of its proper divisors (2140859).

51005509 is a wasteful number, since it uses less digits than its factorization.

51005509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15515.

The product of its (nonzero) digits is 1125, while the sum is 25.

The square root of 51005509 is about 7141.8141252766. The cubic root of 51005509 is about 370.8563292168.

It can be divided in two parts, 5100 and 5509, that added together give a square (10609 = 103²).

The spelling of 51005509 in words is "fifty-one million, five thousand, five hundred nine".