1668449440 has 192 divisors, whose sum is σ = 4737761280. Its totient is φ = 542868480.

The previous prime is 1668449389. The next prime is 1668449443. The reversal of 1668449440 is 449448661.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is not an unprimeable number, because it can be changed into a prime (1668449443) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6156505 + ... + 6156775.

It is an arithmetic number, because the mean of its divisors is an integer number (24675840).

Almost surely, 2^1668449440 is an apocalyptic number.

1668449440 is a gapful number since it is divisible by the number (10) 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 1668449440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2368880640).

1668449440 is an abundant number, since it is smaller than the sum of its proper divisors (3069311840).

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

1668449440 is a wasteful number, since it uses less digits than its factorization.

1668449440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555 (or 547 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 46.

The square root of 1668449440 is about 40846.6576356010. The cubic root of 1668449440 is about 1186.0536931576.

The spelling of 1668449440 in words is "one billion, six hundred sixty-eight million, four hundred forty-nine thousand, four hundred forty".