51001972178 has 4 divisors (see below), whose sum is σ = 76502958270. Its totient is φ = 25500986088.

The previous prime is 51001972171. The next prime is 51001972193. The reversal of 51001972178 is 87127910015.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87127910015 = 5 ⋅17425582003.

It can be written as a sum of positive squares in only one way, i.e., 33460823929 + 17541148249 = 182923^2 + 132443^2 .

It is not an unprimeable number, because it can be changed into a prime (51001972171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12750493043 + ... + 12750493046.

Almost surely, 2^51001972178 is an apocalyptic number.

51001972178 is a deficient number, since it is larger than the sum of its proper divisors (25500986092).

51001972178 is a wasteful number, since it uses less digits than its factorization.

51001972178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25500986091.

The product of its (nonzero) digits is 35280, while the sum is 41.

The spelling of 51001972178 in words is "fifty-one billion, one million, nine hundred seventy-two thousand, one hundred seventy-eight".