4000921 has 8 divisors (see below), whose sum is σ = 4169664. Its totient is φ = 3835440.

The previous prime is 4000907. The next prime is 4000937. The reversal of 4000921 is 1290004.

4000921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 4000921 - 2⁵ = 4000889 is a prime.

It is a Duffinian number.

4000921 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 4000895 and 4000904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4000901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1866 + ... + 3388.

It is an arithmetic number, because the mean of its divisors is an integer number (521208).

Almost surely, 2^4000921 is an apocalyptic number.

It is an amenable number.

4000921 is a deficient number, since it is larger than the sum of its proper divisors (168743).

4000921 is a wasteful number, since it uses less digits than its factorization.

4000921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1631.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 4000921 is about 2000.2302367478. The cubic root of 4000921 is about 158.7522875649.

Adding to 4000921 its reverse (1290004), we get a palindrome (5290925).

The spelling of 4000921 in words is "four million, nine hundred twenty-one", and thus it is an aban number.