1981963 has 2 divisors, whose sum is σ = 1981964. Its totient is φ = 1981962.

The previous prime is 1981949. The next prime is 1981997. The reversal of 1981963 is 3691891.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1981963 is a prime.

It is not a weakly prime, because it can be changed into another prime (1981663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990981 + 990982.

It is an arithmetic number, because the mean of its divisors is an integer number (990982).

2^1981963 is an apocalyptic number.

1981963 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981963 is an equidigital number, since it uses as much as digits as its factorization.

1981963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 37.

The square root of 1981963 is about 1407.8220768265. The cubic root of 1981963 is about 125.6122073886.

The spelling of 1981963 in words is "one million, nine hundred eighty-one thousand, nine hundred sixty-three".