51210720 has 288 divisors, whose sum is σ = 197424864. Its totient is φ = 11980800.

The previous prime is 51210703. The next prime is 51210739. The reversal of 51210720 is 2701215.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 51210693 and 51210702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 839490 + ... + 839550.

It is an arithmetic number, because the mean of its divisors is an integer number (685503).

Almost surely, 2^51210720 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 51210720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98712432).

51210720 is an abundant number, since it is smaller than the sum of its proper divisors (146214144).

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

51210720 is a wasteful number, since it uses less digits than its factorization.

51210720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 135 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 51210720 is about 7156.1665715661. The cubic root of 51210720 is about 371.3530204182.

Adding to 51210720 its reverse (2701215), we get a palindrome (53911935).

The spelling of 51210720 in words is "fifty-one million, two hundred ten thousand, seven hundred twenty".