51302220 has 96 divisors (see below), whose sum is σ = 148490496. Its totient is φ = 13228800.

The previous prime is 51302203. The next prime is 51302221. The reversal of 51302220 is 2220315.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 51302220.

It is not an unprimeable number, because it can be changed into a prime (51302221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 391555 + ... + 391685.

It is an arithmetic number, because the mean of its divisors is an integer number (1546776).

Almost surely, 2^51302220 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 51302220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74245248).

51302220 is an abundant number, since it is smaller than the sum of its proper divisors (97188276).

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

51302220 is a wasteful number, since it uses less digits than its factorization.

51302220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311 (or 309 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 51302220 is about 7162.5568060575. The cubic root of 51302220 is about 371.5740586721.

Adding to 51302220 its reverse (2220315), we get a palindrome (53522535).

The spelling of 51302220 in words is "fifty-one million, three hundred two thousand, two hundred twenty".