45840 has 40 divisors (see below), whose sum is σ = 142848. Its totient is φ = 12160.

The previous prime is 45833. The next prime is 45841. The reversal of 45840 is 4854.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (45841) by changing a digit.

45840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145 + ... + 335.

2⁴⁵⁸⁴⁰ is an apocalyptic number.

45840 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 45840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71424).

45840 is an abundant number, since it is smaller than the sum of its proper divisors (97008).

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

45840 is a wasteful number, since it uses less digits than its factorization.

45840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 45840 is about 214.1027790572. The cubic root of 45840 is about 35.7888878675.

The spelling of 45840 in words is "forty-five thousand, eight hundred forty".