51845439 has 4 divisors (see below), whose sum is σ = 69127256. Its totient is φ = 34563624.

The previous prime is 51845429. The next prime is 51845441. The reversal of 51845439 is 93454815.

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

It is not a de Polignac number, because 51845439 - 2¹⁷ = 51714367 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51845397 and 51845406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51845429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8640904 + ... + 8640909.

It is an arithmetic number, because the mean of its divisors is an integer number (17281814).

Almost surely, 2^51845439 is an apocalyptic number.

51845439 is a deficient number, since it is larger than the sum of its proper divisors (17281817).

51845439 is a wasteful number, since it uses less digits than its factorization.

51845439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17281816.

The product of its digits is 86400, while the sum is 39.

The square root of 51845439 is about 7200.3776984267. The cubic root of 51845439 is about 372.8809405652.

The spelling of 51845439 in words is "fifty-one million, eight hundred forty-five thousand, four hundred thirty-nine".