1668431856 has 160 divisors (see below), whose sum is σ = 5384877568. Its totient is φ = 433382400.

The previous prime is 1668431839. The next prime is 1668431879. The reversal of 1668431856 is 6581348661.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 289806 + ... + 295506.

Almost surely, 2^1668431856 is an apocalyptic number.

1668431856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1668431856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2692438784).

1668431856 is an abundant number, since it is smaller than the sum of its proper divisors (3716445712).

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

1668431856 is a wasteful number, since it uses less digits than its factorization.

1668431856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5799 (or 5793 counting only the distinct ones).

The product of its digits is 829440, while the sum is 48.

The square root of 1668431856 is about 40846.4423909843. The cubic root of 1668431856 is about 1186.0495264863.

The spelling of 1668431856 in words is "one billion, six hundred sixty-eight million, four hundred thirty-one thousand, eight hundred fifty-six".