1661983 has 2 divisors, whose sum is σ = 1661984. Its totient is φ = 1661982.

The previous prime is 1661977. The next prime is 1662007. The reversal of 1661983 is 3891661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1661983 - 2¹³ = 1653791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830991 + 830992.

It is an arithmetic number, because the mean of its divisors is an integer number (830992).

2^1661983 is an apocalyptic number.

1661983 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661983 is an equidigital number, since it uses as much as digits as its factorization.

1661983 is an evil number, because the sum of its binary digits is even.

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

The square root of 1661983 is about 1289.1791962330. The cubic root of 1661983 is about 118.4519439341.

The spelling of 1661983 in words is "one million, six hundred sixty-one thousand, nine hundred eighty-three".