51343220 has 24 divisors (see below), whose sum is σ = 109857384. Its totient is φ = 20149376.

The previous prime is 51343217. The next prime is 51343241. The reversal of 51343220 is 2234315.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 7333264 + 44009956 = 2708^2 + 6634^2 .

It is a super-2 number, since 2×51343220² = 5272252479936800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 51343192 and 51343201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23159 + ... + 25278.

It is an arithmetic number, because the mean of its divisors is an integer number (4577391).

Almost surely, 2^51343220 is an apocalyptic number.

It is an amenable number.

51343220 is an abundant number, since it is smaller than the sum of its proper divisors (58514164).

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

51343220 is a wasteful number, since it uses less digits than its factorization.

51343220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48499 (or 48497 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 51343220 is about 7165.4183408926. The cubic root of 51343220 is about 371.6730178711.

Adding to 51343220 its reverse (2234315), we get a palindrome (53577535).

The spelling of 51343220 in words is "fifty-one million, three hundred forty-three thousand, two hundred twenty".