3645840 has 80 divisors (see below), whose sum is σ = 12338496. Its totient is φ = 883200.

The previous prime is 3645823. The next prime is 3645877. The reversal of 3645840 is 485463.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 3645798 and 3645807.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1950 + ... + 3330.

Almost surely, 2^3645840 is an apocalyptic number.

3645840 is a gapful number since it is divisible by the number (30) 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 3645840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6169248).

3645840 is an abundant number, since it is smaller than the sum of its proper divisors (8692656).

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

3645840 is a wasteful number, since it uses less digits than its factorization.

3645840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1408 (or 1402 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 3645840 is about 1909.4082853073. The cubic root of 3645840 is about 153.9096563488.

The spelling of 3645840 in words is "three million, six hundred forty-five thousand, eight hundred forty".