4004000645 has 8 divisors (see below), whose sum is σ = 4805232120. Its totient is φ = 3202912960.

The previous prime is 4004000617. The next prime is 4004000647. The reversal of 4004000645 is 5460004004.

It is a happy number.

4004000645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 129436129 + 3874564516 = 11377^2 + 62246^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 4004000645 - 2¹⁶ = 4003935109 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 4004000645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4004000647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39851 + ... + 97959.

It is an arithmetic number, because the mean of its divisors is an integer number (600654015).

Almost surely, 2^4004000645 is an apocalyptic number.

It is an amenable number.

4004000645 is a deficient number, since it is larger than the sum of its proper divisors (801231475).

4004000645 is a wasteful number, since it uses less digits than its factorization.

4004000645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71895.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 4004000645 is about 63277.1731748503. The cubic root of 4004000645 is about 1587.9300946382.

Adding to 4004000645 its reverse (5460004004), we get a palindrome (9464004649).

The spelling of 4004000645 in words is "four billion, four million, six hundred forty-five", and thus it is an aban number.