51908638 has 4 divisors (see below), whose sum is σ = 77862960. Its totient is φ = 25954318.

The previous prime is 51908617. The next prime is 51908641. The reversal of 51908638 is 83680915.

It is a happy number.

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

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 51908638.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12977158 + ... + 12977161.

It is an arithmetic number, because the mean of its divisors is an integer number (19465740).

Almost surely, 2^51908638 is an apocalyptic number.

51908638 is a deficient number, since it is larger than the sum of its proper divisors (25954322).

51908638 is a wasteful number, since it uses less digits than its factorization.

51908638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25954321.

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 51908638 is about 7204.7649510584. The cubic root of 51908638 is about 373.0323915836.

The spelling of 51908638 in words is "fifty-one million, nine hundred eight thousand, six hundred thirty-eight".