51422220 has 72 divisors (see below), whose sum is σ = 161375760. Its totient is φ = 13238400.

The previous prime is 51422209. The next prime is 51422233. The reversal of 51422220 is 2222415.

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 = 51422193 and 51422202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 295 + ... + 10145.

It is an arithmetic number, because the mean of its divisors is an integer number (2241330).

Almost surely, 2^51422220 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 51422220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80687880).

51422220 is an abundant number, since it is smaller than the sum of its proper divisors (109953540).

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

51422220 is a wasteful number, since it uses less digits than its factorization.

51422220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9895 (or 9890 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 51422220 is about 7170.9288101333. The cubic root of 51422220 is about 371.8635469015.

Adding to 51422220 its reverse (2222415), we get a palindrome (53644635).

The spelling of 51422220 in words is "fifty-one million, four hundred twenty-two thousand, two hundred twenty".