4000001 has 4 divisors (see below), whose sum is σ = 4097604. Its totient is φ = 3902400.

The previous prime is 3999971. The next prime is 4000037. The reversal of 4000001 is 1000004.

It is a Cunningham number, because it is equal to 2000²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 193600 + 3806401 = 440^2 + 1951^2 .

It is a cyclic number.

It is not a de Polignac number, because 4000001 - 2¹⁸ = 3737857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4000081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48740 + ... + 48821.

It is an arithmetic number, because the mean of its divisors is an integer number (1024401).

Almost surely, 2^4000001 is an apocalyptic number.

4000001 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

4000001 is a deficient number, since it is larger than the sum of its proper divisors (97603).

4000001 is an equidigital number, since it uses as much as digits as its factorization.

4000001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97602.

The product of its (nonzero) digits is 4, while the sum is 5.

The square root of 4000001 is about 2000.0002500000. Note that the first 3 decimals coincide. The cubic root of 4000001 is about 158.7401184252.

Adding to 4000001 its reverse (1000004), we get a palindrome (5000005).

The spelling of 4000001 in words is "four million, one", and thus it is an aban number.