1963781 has 2 divisors, whose sum is σ = 1963782. Its totient is φ = 1963780.

The previous prime is 1963769. The next prime is 1963799. The reversal of 1963781 is 1873691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1934881 + 28900 = 1391^2 + 170^2 .

It is a cyclic number.

It is not a de Polignac number, because 1963781 - 2¹⁴ = 1947397 is a prime.

It is a super-2 number, since 2×1963781² = 7712871631922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1963711) 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, 981890 + 981891.

It is an arithmetic number, because the mean of its divisors is an integer number (981891).

2^1963781 is an apocalyptic number.

It is an amenable number.

1963781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1963781 is an equidigital number, since it uses as much as digits as its factorization.

1963781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 35.

The square root of 1963781 is about 1401.3497065330. The cubic root of 1963781 is about 125.2269158244.

It can be divided in two parts, 1963 and 781, that added together give a cube (2744 = 14³).

The spelling of 1963781 in words is "one million, nine hundred sixty-three thousand, seven hundred eighty-one".