51845440 has 28 divisors (see below), whose sum is σ = 123457716. Its totient is φ = 20738048.

The previous prime is 51845429. The next prime is 51845441. The reversal of 51845440 is 4454815.

It can be written as a sum of positive squares in 2 ways, for example, as 14684224 + 37161216 = 3832^2 + 6096^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51845441) 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, 80689 + ... + 81328.

Almost surely, 2^51845440 is an apocalyptic number.

It is an amenable number.

51845440 is an abundant number, since it is smaller than the sum of its proper divisors (71612276).

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

51845440 is a wasteful number, since it uses less digits than its factorization.

51845440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162034 (or 162024 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 31.

The square root of 51845440 is about 7200.3777678675. The cubic root of 51845440 is about 372.8809429626.

The spelling of 51845440 in words is "fifty-one million, eight hundred forty-five thousand, four hundred forty".