51878421651 has 24 divisors (see below), whose sum is σ = 80478397584. Its totient is φ = 29639688960.

The previous prime is 51878421629. The next prime is 51878421713. The reversal of 51878421651 is 15612487815.

It is not a de Polignac number, because 51878421651 - 2⁵ = 51878421619 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51878421651.

It is not an unprimeable number, because it can be changed into a prime (51878421151) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 924271 + ... + 978791.

It is an arithmetic number, because the mean of its divisors is an integer number (3353266566).

Almost surely, 2^51878421651 is an apocalyptic number.

51878421651 is a deficient number, since it is larger than the sum of its proper divisors (28599975933).

51878421651 is a wasteful number, since it uses less digits than its factorization.

51878421651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61011 (or 61004 counting only the distinct ones).

The product of its digits is 537600, while the sum is 48.

The spelling of 51878421651 in words is "fifty-one billion, eight hundred seventy-eight million, four hundred twenty-one thousand, six hundred fifty-one".