4009381 has 2 divisors, whose sum is σ = 4009382. Its totient is φ = 4009380.

The previous prime is 4009373. The next prime is 4009391. The reversal of 4009381 is 1839004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2873025 + 1136356 = 1695^2 + 1066^2 .

It is a cyclic number.

It is not a de Polignac number, because 4009381 - 2³ = 4009373 is a prime.

It is a super-2 number, since 2×4009381² = 32150272006322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4009321) 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, 2004690 + 2004691.

It is an arithmetic number, because the mean of its divisors is an integer number (2004691).

Almost surely, 2^4009381 is an apocalyptic number.

It is an amenable number.

4009381 is a deficient number, since it is larger than the sum of its proper divisors (1).

4009381 is an equidigital number, since it uses as much as digits as its factorization.

4009381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 4009381 is about 2002.3438765607. The cubic root of 4009381 is about 158.8641033889.

The spelling of 4009381 in words is "four million, nine thousand, three hundred eighty-one".