51091551684 has 144 divisors (see below), whose sum is σ = 140369544000. Its totient is φ = 16068243456.

The previous prime is 51091551683. The next prime is 51091551689. The reversal of 51091551684 is 48615519015.

51091551684 is a `hidden beast` number, since 5 + 1 + 0 + 91 + 551 + 6 + 8 + 4 = 666.

It is a super-2 number, since 2×51091551684² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51091551683) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 10017367 + ... + 10022465.

It is an arithmetic number, because the mean of its divisors is an integer number (974788500).

Almost surely, 2^51091551684 is an apocalyptic number.

51091551684 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 51091551684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70184772000).

51091551684 is an abundant number, since it is smaller than the sum of its proper divisors (89277992316).

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

51091551684 is a wasteful number, since it uses less digits than its factorization.

51091551684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5407 (or 5380 counting only the distinct ones).

The product of its (nonzero) digits is 216000, while the sum is 45.

The spelling of 51091551684 in words is "fifty-one billion, ninety-one million, five hundred fifty-one thousand, six hundred eighty-four".