51491165 has 8 divisors (see below), whose sum is σ = 67406688. Its totient is φ = 37448080.

The previous prime is 51491149. The next prime is 51491183. The reversal of 51491165 is 56119415.

51491165 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 51491165 - 2⁴ = 51491149 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 468047 + ... + 468156.

It is an arithmetic number, because the mean of its divisors is an integer number (8425836).

Almost surely, 2^51491165 is an apocalyptic number.

51491165 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

51491165 is a deficient number, since it is larger than the sum of its proper divisors (15915523).

51491165 is a wasteful number, since it uses less digits than its factorization.

51491165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 936219.

The product of its digits is 5400, while the sum is 32.

The square root of 51491165 is about 7175.7344571828. The cubic root of 51491165 is about 372.0296662856.

The spelling of 51491165 in words is "fifty-one million, four hundred ninety-one thousand, one hundred sixty-five".