1995781 has 2 divisors, whose sum is σ = 1995782. Its totient is φ = 1995780.

The previous prime is 1995769. The next prime is 1995787. The reversal of 1995781 is 1875991.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1779556 + 216225 = 1334^2 + 465^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1995781 is a prime.

It is a super-2 number, since 2×1995781² = 7966283599922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1995787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 997890 + 997891.

It is an arithmetic number, because the mean of its divisors is an integer number (997891).

2^1995781 is an apocalyptic number.

It is an amenable number.

1995781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1995781 is an equidigital number, since it uses as much as digits as its factorization.

1995781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 40.

The square root of 1995781 is about 1412.7211331328. The cubic root of 1995781 is about 125.9034491719.

The spelling of 1995781 in words is "one million, nine hundred ninety-five thousand, seven hundred eighty-one".