1966381 has 2 divisors, whose sum is σ = 1966382. Its totient is φ = 1966380.

The previous prime is 1966343. The next prime is 1966387. The reversal of 1966381 is 1836691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1798281 + 168100 = 1341^2 + 410^2 .

It is an emirp because it is prime and its reverse (1836691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1966381 - 2¹³ = 1958189 is a prime.

It is a super-2 number, since 2×1966381² = 7733308474322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1966387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 983190 + 983191.

It is an arithmetic number, because the mean of its divisors is an integer number (983191).

2^1966381 is an apocalyptic number.

It is an amenable number.

1966381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1966381 is an equidigital number, since it uses as much as digits as its factorization.

1966381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 34.

The square root of 1966381 is about 1402.2770767577. The cubic root of 1966381 is about 125.2821572856.

The spelling of 1966381 in words is "one million, nine hundred sixty-six thousand, three hundred eighty-one".