51381904 has 80 divisors (see below), whose sum is σ = 119420928. Its totient is φ = 20958336.

The previous prime is 51381901. The next prime is 51381907. The reversal of 51381904 is 40918315.

It is an interprime number because it is at equal distance from previous prime (51381901) and next prime (51381907).

It is not an unprimeable number, because it can be changed into a prime (51381901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 226239 + ... + 226465.

Almost surely, 2^51381904 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 51381904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59710464).

51381904 is an abundant number, since it is smaller than the sum of its proper divisors (68039024).

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

51381904 is a wasteful number, since it uses less digits than its factorization.

51381904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332 (or 326 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 51381904 is about 7168.1171865421. The cubic root of 51381904 is about 371.7663387913.

The spelling of 51381904 in words is "fifty-one million, three hundred eighty-one thousand, nine hundred four".