1664001440 has 96 divisors (see below), whose sum is σ = 4124856960. Its totient is φ = 633472000.

The previous prime is 1664001439. The next prime is 1664001461. The reversal of 1664001440 is 441004661.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 326915 + ... + 331965.

It is an arithmetic number, because the mean of its divisors is an integer number (42967260).

Almost surely, 2^1664001440 is an apocalyptic number.

1664001440 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 1664001440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2062428480).

1664001440 is an abundant number, since it is smaller than the sum of its proper divisors (2460855520).

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

1664001440 is a wasteful number, since it uses less digits than its factorization.

1664001440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5166 (or 5158 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 1664001440 is about 40792.1737591906. The cubic root of 1664001440 is about 1184.9987691893.

The spelling of 1664001440 in words is "one billion, six hundred sixty-four million, one thousand, four hundred forty".