51440308920 has 1152 divisors, whose sum is σ = 238419417600. Its totient is φ = 9333688320.

The previous prime is 51440308919. The next prime is 51440308961. The reversal of 51440308920 is 2980304415.

51440308920 is a `hidden beast` number, since 514 + 40 + 3 + 0 + 89 + 20 = 666.

It is a super-2 number, since 2×51440308920² (a number of 22 digits) contains 22 as substring.

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

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 287 ways as a sum of consecutive naturals, for example, 75314899 + ... + 75315581.

It is an arithmetic number, because the mean of its divisors is an integer number (206961300).

Almost surely, 2^51440308920 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 51440308920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119209708800).

51440308920 is an abundant number, since it is smaller than the sum of its proper divisors (186979108680).

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

51440308920 is a wasteful number, since it uses less digits than its factorization.

51440308920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761 (or 743 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 51440308920 in words is "fifty-one billion, four hundred forty million, three hundred eight thousand, nine hundred twenty".