4001638 has 8 divisors (see below), whose sum is σ = 6064632. Its totient is φ = 1980096.

The previous prime is 4001629. The next prime is 4001639. The reversal of 4001638 is 8361004.

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

4001638 is a modest number, since divided by 1638 gives 4 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4001639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10120 + ... + 10507.

It is an arithmetic number, because the mean of its divisors is an integer number (758079).

Almost surely, 2^4001638 is an apocalyptic number.

4001638 is a deficient number, since it is larger than the sum of its proper divisors (2062994).

4001638 is a wasteful number, since it uses less digits than its factorization.

4001638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20726.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 4001638 is about 2000.4094580860. The cubic root of 4001638 is about 158.7617702642.

The spelling of 4001638 in words is "four million, one thousand, six hundred thirty-eight".