51984391 has 4 divisors (see below), whose sum is σ = 52001712. Its totient is φ = 51967072.

The previous prime is 51984367. The next prime is 51984421. The reversal of 51984391 is 19348915.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51984391 is a prime.

It is a super-3 number, since 3×51984391³ (a number of 24 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51984341) 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 3 ways as a sum of consecutive naturals, for example, 2866 + ... + 10591.

It is an arithmetic number, because the mean of its divisors is an integer number (13000428).

Almost surely, 2^51984391 is an apocalyptic number.

51984391 is a deficient number, since it is larger than the sum of its proper divisors (17321).

51984391 is a wasteful number, since it uses less digits than its factorization.

51984391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17320.

The product of its digits is 38880, while the sum is 40.

The square root of 51984391 is about 7210.0201802769. The cubic root of 51984391 is about 373.2137652990.

The spelling of 51984391 in words is "fifty-one million, nine hundred eighty-four thousand, three hundred ninety-one".