51383640 has 256 divisors, whose sum is σ = 197406720. Its totient is φ = 10391040.

The previous prime is 51383617. The next prime is 51383669. The reversal of 51383640 is 4638315.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 51383598 and 51383607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 619039 + ... + 619121.

It is an arithmetic number, because the mean of its divisors is an integer number (771120).

Almost surely, 2^51383640 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 51383640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98703360).

51383640 is an abundant number, since it is smaller than the sum of its proper divisors (146023080).

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

51383640 is a wasteful number, since it uses less digits than its factorization.

51383640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 51383640 is about 7168.2382772896. The cubic root of 51383640 is about 371.7705256032.

It can be divided in two parts, 5138 and 3640, that added together give a palindrome (8778).

The spelling of 51383640 in words is "fifty-one million, three hundred eighty-three thousand, six hundred forty".