1668261644 has 36 divisors (see below), whose sum is σ = 3439124640. Its totient is φ = 705912480.

The previous prime is 1668261643. The next prime is 1668261649. The reversal of 1668261644 is 4461628661.

It is a junction number, because it is equal to n+sod(n) for n = 1668261595 and 1668261604.

It is not an unprimeable number, because it can be changed into a prime (1668261643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38387 + ... + 69354.

It is an arithmetic number, because the mean of its divisors is an integer number (95531240).

Almost surely, 2^1668261644 is an apocalyptic number.

1668261644 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1668261644 is an abundant number, since it is smaller than the sum of its proper divisors (1770862996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1668261644 is a wasteful number, since it uses less digits than its factorization.

1668261644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107838 (or 107829 counting only the distinct ones).

The product of its digits is 331776, while the sum is 44.

The square root of 1668261644 is about 40844.3587781716. The cubic root of 1668261644 is about 1186.0091918597.

The spelling of 1668261644 in words is "one billion, six hundred sixty-eight million, two hundred sixty-one thousand, six hundred forty-four".