51489191 has 4 divisors (see below), whose sum is σ = 55449912. Its totient is φ = 47528472.

The previous prime is 51489173. The next prime is 51489197. The reversal of 51489191 is 19198415.

51489191 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19198415 = 5 ⋅3839683.

It is a cyclic number.

It is not a de Polignac number, because 51489191 - 2⁶ = 51489127 is a prime.

It is a super-2 number, since 2×51489191² = 5302273579668962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51489197) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1980341 + ... + 1980366.

It is an arithmetic number, because the mean of its divisors is an integer number (13862478).

Almost surely, 2^51489191 is an apocalyptic number.

51489191 is a deficient number, since it is larger than the sum of its proper divisors (3960721).

51489191 is a wasteful number, since it uses less digits than its factorization.

51489191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3960720.

The product of its digits is 12960, while the sum is 38.

The square root of 51489191 is about 7175.5969089686. The cubic root of 51489191 is about 372.0249120982.

The spelling of 51489191 in words is "fifty-one million, four hundred eighty-nine thousand, one hundred ninety-one".