1683742661 has 4 divisors (see below), whose sum is σ = 1683831072. Its totient is φ = 1683654252.

The previous prime is 1683742657. The next prime is 1683742663. The reversal of 1683742661 is 1662473861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1662473861 = 5581 ⋅297881.

It is a cyclic number.

It is not a de Polignac number, because 1683742661 - 2² = 1683742657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1683742663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2561 + ... + 58086.

It is an arithmetic number, because the mean of its divisors is an integer number (420957768).

Almost surely, 2^1683742661 is an apocalyptic number.

It is an amenable number.

1683742661 is a deficient number, since it is larger than the sum of its proper divisors (88411).

1683742661 is an equidigital number, since it uses as much as digits as its factorization.

1683742661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88410.

The product of its digits is 290304, while the sum is 44.

The square root of 1683742661 is about 41033.4334537094. The cubic root of 1683742661 is about 1189.6665169630. Note that the first 3 decimals are identical.

The spelling of 1683742661 in words is "one billion, six hundred eighty-three million, seven hundred forty-two thousand, six hundred sixty-one".