1906381 has 2 divisors, whose sum is σ = 1906382. Its totient is φ = 1906380.

The previous prime is 1906379. The next prime is 1906391. The reversal of 1906381 is 1836091.

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., 1069156 + 837225 = 1034^2 + 915^2 .

It is an emirp because it is prime and its reverse (1836091) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1906381 - 2¹ = 1906379 is a prime.

It is a super-2 number, since 2×1906381² = 7268577034322, which contains 22 as substring.

Together with 1906379, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1906321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 953190 + 953191.

It is an arithmetic number, because the mean of its divisors is an integer number (953191).

2^1906381 is an apocalyptic number.

It is an amenable number.

1906381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1906381 is an equidigital number, since it uses as much as digits as its factorization.

1906381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 1906381 is about 1380.7175670643. The cubic root of 1906381 is about 123.9947318261.

The spelling of 1906381 in words is "one million, nine hundred six thousand, three hundred eighty-one".