4021081 has 2 divisors, whose sum is σ = 4021082. Its totient is φ = 4021080.

The previous prime is 4021079. The next prime is 4021091. The reversal of 4021081 is 1801204.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3553225 + 467856 = 1885^2 + 684^2 .

It is a cyclic number.

It is not a de Polignac number, because 4021081 - 2¹ = 4021079 is a prime.

It is a super-2 number, since 2×4021081² = 32338184817122, which contains 22 as substring.

Together with 4021079, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (4021001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2010540 + 2010541.

It is an arithmetic number, because the mean of its divisors is an integer number (2010541).

Almost surely, 2^4021081 is an apocalyptic number.

It is an amenable number.

4021081 is a deficient number, since it is larger than the sum of its proper divisors (1).

4021081 is an equidigital number, since it uses as much as digits as its factorization.

4021081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 4021081 is about 2005.2633243542. The cubic root of 4021081 is about 159.0184834069.

Adding to 4021081 its reverse (1801204), we get a palindrome (5822285).

The spelling of 4021081 in words is "four million, twenty-one thousand, eighty-one".