1668403647 has 54 divisors (see below), whose sum is σ = 2687411688. Its totient is φ = 995330688.

The previous prime is 1668403643. The next prime is 1668403657. The reversal of 1668403647 is 7463048661.

It is a happy number.

It is not a de Polignac number, because 1668403647 - 2² = 1668403643 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668403643) 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 53 ways as a sum of consecutive naturals, for example, 9990358 + ... + 9990524.

Almost surely, 2^1668403647 is an apocalyptic number.

1668403647 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

1668403647 is a deficient number, since it is larger than the sum of its proper divisors (1019008041).

1668403647 is a wasteful number, since it uses less digits than its factorization.

1668403647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397 (or 210 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The square root of 1668403647 is about 40846.0970840544. The cubic root of 1668403647 is about 1186.0428420739.

The spelling of 1668403647 in words is "one billion, six hundred sixty-eight million, four hundred three thousand, six hundred forty-seven".