4000000 has 63 divisors (see below), whose sum is σ = 9980341. Its totient is φ = 1600000.

The previous prime is 3999971. The next prime is 4000037. The reversal of 4000000 is 4.

The square root of 4000000 is 2000.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 3 ways, for example, as 3504384 + 495616 = 1872^2 + 704^2 .

It is a Harshad number since it is a multiple of its sum of digits (4).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 6 ways as a sum of consecutive naturals, for example, 799998 + ... + 800002.

Almost surely, 2^4000000 is an apocalyptic number.

4000000 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

4000000 is the 2000-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 4000000

4000000 is an abundant number, since it is smaller than the sum of its proper divisors (5980341).

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

4000000 is an frugal number, since it uses more digits than its factorization.

4000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46 (or 7 counting only the distinct ones).

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

The cubic root of 4000000 is about 158.7401051968.

The spelling of 4000000 in words is "four million", and thus it is an aban number and an eban number.