51981673536 has 336 divisors, whose sum is σ = 170485905408. Its totient is φ = 15601766400.

The previous prime is 51981673409. The next prime is 51981673553. The reversal of 51981673536 is 63537618915.

51981673536 is a `hidden beast` number, since 5 + 1 + 98 + 16 + 7 + 3 + 536 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8286081 + ... + 8292351.

It is an arithmetic number, because the mean of its divisors is an integer number (507398528).

Almost surely, 2^51981673536 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 51981673536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85242952704).

51981673536 is an abundant number, since it is smaller than the sum of its proper divisors (118504231872).

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

51981673536 is a wasteful number, since it uses less digits than its factorization.

51981673536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6352 (or 6330 counting only the distinct ones).

The product of its digits is 4082400, while the sum is 54.

The spelling of 51981673536 in words is "fifty-one billion, nine hundred eighty-one million, six hundred seventy-three thousand, five hundred thirty-six".