51938640 has 240 divisors, whose sum is σ = 194987520. Its totient is φ = 12303360.

The previous prime is 51938617. The next prime is 51938641. The reversal of 51938640 is 4683915.

51938640 is a `hidden beast` number, since 5 + 1 + 9 + 3 + 8 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a junction number, because it is equal to n+sod(n) for n = 51938595 and 51938604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51938641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 290071 + ... + 290249.

It is an arithmetic number, because the mean of its divisors is an integer number (812448).

Almost surely, 2^51938640 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 51938640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97493760).

51938640 is an abundant number, since it is smaller than the sum of its proper divisors (143048880).

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

51938640 is a wasteful number, since it uses less digits than its factorization.

51938640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 51938640 is about 7206.8467445895. The cubic root of 51938640 is about 373.1042457922.

The spelling of 51938640 in words is "fifty-one million, nine hundred thirty-eight thousand, six hundred forty".