51164155440 has 480 divisors, whose sum is σ = 184505857536. Its totient is φ = 13168189440.

The previous prime is 51164155429. The next prime is 51164155459. The reversal of 51164155440 is 4455146115.

51164155440 is a `hidden beast` number, since 5 + 1 + 1 + 64 + 1 + 554 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 51164155395 and 51164155404.

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 95 ways as a sum of consecutive naturals, for example, 81083925 + ... + 81084555.

Almost surely, 2^51164155440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51164155440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92252928768).

51164155440 is an abundant number, since it is smaller than the sum of its proper divisors (133341702096).

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

51164155440 is a wasteful number, since it uses less digits than its factorization.

51164155440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799 (or 781 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 36.

The spelling of 51164155440 in words is "fifty-one billion, one hundred sixty-four million, one hundred fifty-five thousand, four hundred forty".