51820540 has 12 divisors (see below), whose sum is σ = 108823176. Its totient is φ = 20728208.

The previous prime is 51820529. The next prime is 51820553. The reversal of 51820540 is 4502815.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1295494 + ... + 1295533.

It is an arithmetic number, because the mean of its divisors is an integer number (9068598).

Almost surely, 2^51820540 is an apocalyptic number.

It is an amenable number.

51820540 is an abundant number, since it is smaller than the sum of its proper divisors (57002636).

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

51820540 is a wasteful number, since it uses less digits than its factorization.

51820540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2591036 (or 2591034 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 51820540 is about 7198.6484842643. The cubic root of 51820540 is about 372.8212384365.

The spelling of 51820540 in words is "fifty-one million, eight hundred twenty thousand, five hundred forty".