51748978 has 4 divisors (see below), whose sum is σ = 77623470. Its totient is φ = 25874488.

The previous prime is 51748973. The next prime is 51748987. The reversal of 51748978 is 87984715.

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

It can be written as a sum of positive squares in only one way, i.e., 34963569 + 16785409 = 5913^2 + 4097^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (51748973) 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 as a sum of consecutive naturals, namely, 12937243 + ... + 12937246.

Almost surely, 2^51748978 is an apocalyptic number.

51748978 is a deficient number, since it is larger than the sum of its proper divisors (25874492).

51748978 is a wasteful number, since it uses less digits than its factorization.

51748978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25874491.

The product of its digits is 564480, while the sum is 49.

The square root of 51748978 is about 7193.6762507080. The cubic root of 51748978 is about 372.6495425276.

The spelling of 51748978 in words is "fifty-one million, seven hundred forty-eight thousand, nine hundred seventy-eight".