4006638 has 16 divisors (see below), whose sum is σ = 8903760. Its totient is φ = 1335528.

The previous prime is 4006637. The next prime is 4006649. The reversal of 4006638 is 8366004.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4006633) 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 7 ways as a sum of consecutive naturals, for example, 37045 + ... + 37152.

It is an arithmetic number, because the mean of its divisors is an integer number (556485).

Almost surely, 2^4006638 is an apocalyptic number.

4006638 is an abundant number, since it is smaller than the sum of its proper divisors (4897122).

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

4006638 is a wasteful number, since it uses less digits than its factorization.

4006638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74208 (or 74202 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 4006638 is about 2001.6588120856. The cubic root of 4006638 is about 158.8278664030.

It can be divided in two parts, 40066 and 38, that added together give a palindrome (40104).

The spelling of 4006638 in words is "four million, six thousand, six hundred thirty-eight".