1664398387200 has 576 divisors, whose sum is σ = 5587099277760. Its totient is φ = 437059584000.

The previous prime is 1664398387199. The next prime is 1664398387231. The reversal of 1664398387200 is 27838934661.

It is a super-2 number, since 2×1664398387200² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3642009372 + ... + 3642009828.

It is an arithmetic number, because the mean of its divisors is an integer number (9699825135).

Almost surely, 2^{1664398387200} is an apocalyptic number.

1664398387200 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 1664398387200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2793549638880).

1664398387200 is an abundant number, since it is smaller than the sum of its proper divisors (3922700890560).

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

1664398387200 is a wasteful number, since it uses less digits than its factorization.

1664398387200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 804 (or 779 counting only the distinct ones).

The product of its (nonzero) digits is 10450944, while the sum is 57.

The spelling of 1664398387200 in words is "one trillion, six hundred sixty-four billion, three hundred ninety-eight million, three hundred eighty-seven thousand, two hundred".