51840340 has 24 divisors (see below), whose sum is σ = 109067112. Its totient is φ = 20697600.

The previous prime is 51840337. The next prime is 51840377. The reversal of 51840340 is 4304815.

It can be written as a sum of positive squares in 4 ways, for example, as 3370896 + 48469444 = 1836^2 + 6962^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10240 + ... + 14440.

It is an arithmetic number, because the mean of its divisors is an integer number (4544463).

Almost surely, 2^51840340 is an apocalyptic number.

It is an amenable number.

51840340 is an abundant number, since it is smaller than the sum of its proper divisors (57226772).

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

51840340 is a wasteful number, since it uses less digits than its factorization.

51840340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4827 (or 4825 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 51840340 is about 7200.0236110724. The cubic root of 51840340 is about 372.8687158817.

The spelling of 51840340 in words is "fifty-one million, eight hundred forty thousand, three hundred forty".