51979646384640 has 1600 divisors, whose sum is σ = 213182607939840. Its totient is φ = 11991711744000.

The previous prime is 51979646384639. The next prime is 51979646384647. The reversal of 51979646384640 is 4648364697915.

51979646384640 is a `hidden beast` number, since 5 + 1 + 9 + 7 + 96 + 46 + 38 + 464 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is not an unprimeable number, because it can be changed into a prime (51979646384647) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 11502464301 + ... + 11502468819.

Almost surely, 2^{51979646384640} 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 51979646384640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106591303969920).

51979646384640 is an abundant number, since it is smaller than the sum of its proper divisors (161202961555200).

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

51979646384640 is a wasteful number, since it uses less digits than its factorization.

51979646384640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4835 (or 4810 counting only the distinct ones).

The product of its (nonzero) digits is 940584960, while the sum is 72.

The spelling of 51979646384640 in words is "fifty-one trillion, nine hundred seventy-nine billion, six hundred forty-six million, three hundred eighty-four thousand, six hundred forty".