4006381 has 2 divisors, whose sum is σ = 4006382. Its totient is φ = 4006380.

The previous prime is 4006363. The next prime is 4006403. The reversal of 4006381 is 1836004.

It is an a-pointer prime, because the next prime (4006403) can be obtained adding 4006381 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3572100 + 434281 = 1890^2 + 659^2 .

It is a cyclic number.

It is not a de Polignac number, because 4006381 - 2⁵ = 4006349 is a prime.

It is a super-2 number, since 2×4006381² = 32102177434322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4006351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2003190 + 2003191.

It is an arithmetic number, because the mean of its divisors is an integer number (2003191).

Almost surely, 2^4006381 is an apocalyptic number.

It is an amenable number.

4006381 is a deficient number, since it is larger than the sum of its proper divisors (1).

4006381 is an equidigital number, since it uses as much as digits as its factorization.

4006381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 4006381 is about 2001.5946143013. The cubic root of 4006381 is about 158.8244704025.

The spelling of 4006381 in words is "four million, six thousand, three hundred eighty-one".