51878504042 has 4 divisors (see below), whose sum is σ = 77817756066. Its totient is φ = 25939252020.

The previous prime is 51878504033. The next prime is 51878504063. The reversal of 51878504042 is 24040587815.

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., 43259424121 + 8619079921 = 207989^2 + 92839^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51878503984 and 51878504002.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12969626009 + ... + 12969626012.

Almost surely, 2^51878504042 is an apocalyptic number.

51878504042 is a deficient number, since it is larger than the sum of its proper divisors (25939252024).

51878504042 is a wasteful number, since it uses less digits than its factorization.

51878504042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25939252023.

The product of its (nonzero) digits is 358400, while the sum is 44.

The spelling of 51878504042 in words is "fifty-one billion, eight hundred seventy-eight million, five hundred four thousand, forty-two".