51138555380 has 24 divisors (see below), whose sum is σ = 117153781920. Its totient is φ = 18595838240.

The previous prime is 51138555379. The next prime is 51138555421. The reversal of 51138555380 is 8355583115.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 116223770 + ... + 116224209.

It is an arithmetic number, because the mean of its divisors is an integer number (4881407580).

Almost surely, 2^51138555380 is an apocalyptic number.

It is an amenable number.

51138555380 is an abundant number, since it is smaller than the sum of its proper divisors (66015226540).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51138555380 is a wasteful number, since it uses less digits than its factorization.

51138555380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232447999 (or 232447997 counting only the distinct ones).

The product of its (nonzero) digits is 360000, while the sum is 44.

The spelling of 51138555380 in words is "fifty-one billion, one hundred thirty-eight million, five hundred fifty-five thousand, three hundred eighty".