51516020 has 12 divisors (see below), whose sum is σ = 108183684. Its totient is φ = 20606400.

The previous prime is 51516019. The next prime is 51516029. The reversal of 51516020 is 2061515.

It can be written as a sum of positive squares in 2 ways, for example, as 28686736 + 22829284 = 5356^2 + 4778^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 2575801 = 51516020 / (5 + 1 + 5 + 1 + 6 + 0 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 51515983 and 51516001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51516029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1287881 + ... + 1287920.

It is an arithmetic number, because the mean of its divisors is an integer number (9015307).

Almost surely, 2^51516020 is an apocalyptic number.

It is an amenable number.

51516020 is an abundant number, since it is smaller than the sum of its proper divisors (56667664).

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

51516020 is a wasteful number, since it uses less digits than its factorization.

51516020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2575810 (or 2575808 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 51516020 is about 7177.4661267052. The cubic root of 51516020 is about 372.0895167469.

Adding to 51516020 its reverse (2061515), we get a palindrome (53577535).

The spelling of 51516020 in words is "fifty-one million, five hundred sixteen thousand, twenty".