4090921 has 2 divisors, whose sum is σ = 4090922. Its totient is φ = 4090920.

The previous prime is 4090913. The next prime is 4090937. The reversal of 4090921 is 1290904.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2624400 + 1466521 = 1620^2 + 1211^2 .

It is a cyclic number.

It is not a de Polignac number, because 4090921 - 2³ = 4090913 is a prime.

It is not a weakly prime, because it can be changed into another prime (4090901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2045460 + 2045461.

It is an arithmetic number, because the mean of its divisors is an integer number (2045461).

Almost surely, 2^4090921 is an apocalyptic number.

It is an amenable number.

4090921 is a deficient number, since it is larger than the sum of its proper divisors (1).

4090921 is an equidigital number, since it uses as much as digits as its factorization.

4090921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 4090921 is about 2022.6025313936. The cubic root of 4090921 is about 159.9338398340.

The spelling of 4090921 in words is "four million, ninety thousand, nine hundred twenty-one".