51045220 has 96 divisors (see below), whose sum is σ = 121927680. Its totient is φ = 17848320.

The previous prime is 51045209. The next prime is 51045301. The reversal of 51045220 is 2254015.

It is a super-2 number, since 2×51045220² = 5211228969696800, which contains 22 as substring.

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, 305577 + ... + 305743.

It is an arithmetic number, because the mean of its divisors is an integer number (1270080).

Almost surely, 2^51045220 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 51045220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60963840).

51045220 is an abundant number, since it is smaller than the sum of its proper divisors (70882460).

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

51045220 is a wasteful number, since it uses less digits than its factorization.

51045220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 51045220 is about 7144.5937603198. The cubic root of 51045220 is about 370.9525492504.

Adding to 51045220 its reverse (2254015), we get a palindrome (53299235).

The spelling of 51045220 in words is "fifty-one million, forty-five thousand, two hundred twenty".