4005121 has 2 divisors, whose sum is σ = 4005122. Its totient is φ = 4005120.

The previous prime is 4005119. The next prime is 4005137. The reversal of 4005121 is 1215004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2873025 + 1132096 = 1695^2 + 1064^2 .

It is a cyclic number.

It is not a de Polignac number, because 4005121 - 2¹ = 4005119 is a prime.

Together with 4005119, it forms a pair of twin primes.

4005121 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (4005821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2002560 + 2002561.

It is an arithmetic number, because the mean of its divisors is an integer number (2002561).

Almost surely, 2^4005121 is an apocalyptic number.

It is an amenable number.

4005121 is a deficient number, since it is larger than the sum of its proper divisors (1).

4005121 is an equidigital number, since it uses as much as digits as its factorization.

4005121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 4005121 is about 2001.2798405021. The cubic root of 4005121 is about 158.8078186482.

The spelling of 4005121 in words is "four million, five thousand, one hundred twenty-one".