51381756 has 96 divisors (see below), whose sum is σ = 139776000. Its totient is φ = 16303680.

The previous prime is 51381749. The next prime is 51381797. The reversal of 51381756 is 65718315.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 51381756.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 344770 + ... + 344918.

It is an arithmetic number, because the mean of its divisors is an integer number (1456000).

Almost surely, 2^51381756 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 51381756, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69888000).

51381756 is an abundant number, since it is smaller than the sum of its proper divisors (88394244).

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

51381756 is a wasteful number, since it uses less digits than its factorization.

51381756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296 (or 288 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The square root of 51381756 is about 7168.1068630427. The cubic root of 51381756 is about 371.7659818467.

The spelling of 51381756 in words is "fifty-one million, three hundred eighty-one thousand, seven hundred fifty-six".