51103220 has 96 divisors (see below), whose sum is σ = 130394880. Its totient is φ = 16450560.

The previous prime is 51103201. The next prime is 51103237. The reversal of 51103220 is 2230115.

It is a happy number.

It is a super-2 number, since 2×51103220² = 5223078188736800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 51103195 and 51103204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 166307 + ... + 166613.

It is an arithmetic number, because the mean of its divisors is an integer number (1358280).

Almost surely, 2^51103220 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 51103220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65197440).

51103220 is an abundant number, since it is smaller than the sum of its proper divisors (79291660).

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

51103220 is a wasteful number, since it uses less digits than its factorization.

51103220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 391 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 51103220 is about 7148.6516211101. The cubic root of 51103220 is about 371.0929940306.

Adding to 51103220 its reverse (2230115), we get a palindrome (53333335).

The spelling of 51103220 in words is "fifty-one million, one hundred three thousand, two hundred twenty".