51439863 has 4 divisors (see below), whose sum is σ = 68586488. Its totient is φ = 34293240.

The previous prime is 51439849. The next prime is 51439867. The reversal of 51439863 is 36893415.

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

It is not a de Polignac number, because 51439863 - 2⁹ = 51439351 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51439867) 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, 8573308 + ... + 8573313.

It is an arithmetic number, because the mean of its divisors is an integer number (17146622).

Almost surely, 2^51439863 is an apocalyptic number.

51439863 is a deficient number, since it is larger than the sum of its proper divisors (17146625).

51439863 is a wasteful number, since it uses less digits than its factorization.

51439863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17146624.

The product of its digits is 77760, while the sum is 39.

The square root of 51439863 is about 7172.1588800026. The cubic root of 51439863 is about 371.9060709204.

The spelling of 51439863 in words is "fifty-one million, four hundred thirty-nine thousand, eight hundred sixty-three".