51391585 has 16 divisors (see below), whose sum is σ = 71638272. Its totient is φ = 34660800.

The previous prime is 51391547. The next prime is 51391597. The reversal of 51391585 is 58519315.

It is not a de Polignac number, because 51391585 - 2⁹ = 51391073 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9901 + ... + 14170.

It is an arithmetic number, because the mean of its divisors is an integer number (4477392).

Almost surely, 2^51391585 is an apocalyptic number.

It is an amenable number.

51391585 is a deficient number, since it is larger than the sum of its proper divisors (20246687).

51391585 is a wasteful number, since it uses less digits than its factorization.

51391585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24144.

The product of its digits is 27000, while the sum is 37.

The square root of 51391585 is about 7168.7924366660. The cubic root of 51391585 is about 371.7896858171.

It can be divided in two parts, 5139 and 1585, that added together give a square (6724 = 82²).

The spelling of 51391585 in words is "fifty-one million, three hundred ninety-one thousand, five hundred eighty-five".