51004820 has 24 divisors (see below), whose sum is σ = 109724328. Its totient is φ = 19904000.

The previous prime is 51004817. The next prime is 51004829. The reversal of 51004820 is 2840015.

It can be written as a sum of positive squares in 4 ways, for example, as 2172676 + 48832144 = 1474^2 + 6988^2 .

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 = 51004792 and 51004801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51004829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30281 + ... + 31920.

It is an arithmetic number, because the mean of its divisors is an integer number (4571847).

Almost surely, 2^51004820 is an apocalyptic number.

It is an amenable number.

51004820 is an abundant number, since it is smaller than the sum of its proper divisors (58719508).

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

51004820 is a wasteful number, since it uses less digits than its factorization.

51004820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62251 (or 62249 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 51004820 is about 7141.7658880700. The cubic root of 51004820 is about 370.8546593243.

Adding to 51004820 its reverse (2840015), we get a palindrome (53844835).

The spelling of 51004820 in words is "fifty-one million, four thousand, eight hundred twenty".