1668739837 has 4 divisors (see below), whose sum is σ = 1726282620. Its totient is φ = 1611197056.

The previous prime is 1668739823. The next prime is 1668739867. The reversal of 1668739837 is 7389378661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 402162916 + 1266576921 = 20054^2 + 35589^2 .

It is a cyclic number.

It is not a de Polignac number, because 1668739837 - 2¹⁵ = 1668707069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668739867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28771348 + ... + 28771405.

It is an arithmetic number, because the mean of its divisors is an integer number (431570655).

Almost surely, 2^1668739837 is an apocalyptic number.

It is an amenable number.

1668739837 is a deficient number, since it is larger than the sum of its proper divisors (57542783).

1668739837 is an equidigital number, since it uses as much as digits as its factorization.

1668739837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57542782.

The product of its digits is 9144576, while the sum is 58.

The square root of 1668739837 is about 40850.2122026312. The cubic root of 1668739837 is about 1186.1225008472.

The spelling of 1668739837 in words is "one billion, six hundred sixty-eight million, seven hundred thirty-nine thousand, eight hundred thirty-seven".