51821509791744 has 2080 divisors, whose sum is σ = 204466357877760. Its totient is φ = 12670127308800.

The previous prime is 51821509791713. The next prime is 51821509791787. The reversal of 51821509791744 is 44719790512815.

51821509791744 is a `hidden beast` number, since 5 + 1 + 8 + 2 + 1 + 509 + 79 + 17 + 44 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 116978577187 + ... + 116978577629.

Almost surely, 2^{51821509791744} is an apocalyptic number.

51821509791744 is a gapful number since it is divisible by the number (54) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51821509791744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102233178938880).

51821509791744 is an abundant number, since it is smaller than the sum of its proper divisors (152644848086016).

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

51821509791744 is a wasteful number, since it uses less digits than its factorization.

51821509791744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 757 (or 726 counting only the distinct ones).

The product of its (nonzero) digits is 25401600, while the sum is 63.

The spelling of 51821509791744 in words is "fifty-one trillion, eight hundred twenty-one billion, five hundred nine million, seven hundred ninety-one thousand, seven hundred forty-four".