1691983 has 2 divisors, whose sum is σ = 1691984. Its totient is φ = 1691982.

The previous prime is 1691939. The next prime is 1692013. The reversal of 1691983 is 3891961.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1691983 is a prime.

1691983 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1691933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845991 + 845992.

It is an arithmetic number, because the mean of its divisors is an integer number (845992).

2^1691983 is an apocalyptic number.

1691983 is a deficient number, since it is larger than the sum of its proper divisors (1).

1691983 is an equidigital number, since it uses as much as digits as its factorization.

1691983 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 1691983 is about 1300.7624687083. The cubic root of 1691983 is about 119.1604126232.

The spelling of 1691983 in words is "one million, six hundred ninety-one thousand, nine hundred eighty-three".