3645978 has 32 divisors (see below), whose sum is σ = 8515584. Its totient is φ = 1018992.

The previous prime is 3645977. The next prime is 3645979. The reversal of 3645978 is 8795463.

It is a happy number.

3645978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (3645977) and next prime (3645979).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a d-powerful number, because it can be written as 3¹³ + 6³ + 4⁶ + 5⁹ + 9⁵ + 7⁴ + 8⁵ .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3645977) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1051 + ... + 2897.

It is an arithmetic number, because the mean of its divisors is an integer number (266112).

Almost surely, 2^3645978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3645978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4257792).

3645978 is an abundant number, since it is smaller than the sum of its proper divisors (4869606).

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

3645978 is a wasteful number, since it uses less digits than its factorization.

3645978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1906.

The product of its digits is 181440, while the sum is 42.

The square root of 3645978 is about 1909.4444218149. Note that the first 4 decimals coincide. The cubic root of 3645978 is about 153.9115982209.

The spelling of 3645978 in words is "three million, six hundred forty-five thousand, nine hundred seventy-eight".