51388438 has 4 divisors (see below), whose sum is σ = 77082660. Its totient is φ = 25694218.

The previous prime is 51388427. The next prime is 51388453. The reversal of 51388438 is 83488315.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83488315 = 5 ⋅16697663.

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 self number, because there is not a number n which added to its sum of digits gives 51388438.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12847108 + ... + 12847111.

It is an arithmetic number, because the mean of its divisors is an integer number (19270665).

Almost surely, 2^51388438 is an apocalyptic number.

51388438 is a deficient number, since it is larger than the sum of its proper divisors (25694222).

51388438 is a wasteful number, since it uses less digits than its factorization.

51388438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25694221.

The product of its digits is 92160, while the sum is 40.

The square root of 51388438 is about 7168.5729402720. The cubic root of 51388438 is about 371.7820967275.

The spelling of 51388438 in words is "fifty-one million, three hundred eighty-eight thousand, four hundred thirty-eight".