51159068640 has 480 divisors, whose sum is σ = 190903093920. Its totient is φ = 12866605056.

The previous prime is 51159068633. The next prime is 51159068641. The reversal of 51159068640 is 4686095115.

51159068640 is a `hidden beast` number, since 5 + 11 + 590 + 6 + 8 + 6 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a super-2 number, since 2×51159068640² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51159068641) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 91847242 + ... + 91847798.

It is an arithmetic number, because the mean of its divisors is an integer number (397714779).

Almost surely, 2^51159068640 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 51159068640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95451546960).

51159068640 is an abundant number, since it is smaller than the sum of its proper divisors (139744025280).

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

51159068640 is a wasteful number, since it uses less digits than its factorization.

51159068640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 976 (or 959 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The spelling of 51159068640 in words is "fifty-one billion, one hundred fifty-nine million, sixty-eight thousand, six hundred forty".