1664357990400 has 1728 divisors, whose sum is σ = 7370460358560. Its totient is φ = 356725555200.

The previous prime is 1664357990387. The next prime is 1664357990419. The reversal of 1664357990400 is 40997534661.

1664357990400 is a `hidden beast` number, since 1 + 6 + 64 + 3 + 579 + 9 + 0 + 4 + 0 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 6141542265 + ... + 6141542535.

Almost surely, 2^{1664357990400} is an apocalyptic number.

1664357990400 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 1664357990400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3685230179280).

1664357990400 is an abundant number, since it is smaller than the sum of its proper divisors (5706102368160).

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

1664357990400 is a wasteful number, since it uses less digits than its factorization.

1664357990400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348 (or 305 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 54.

The spelling of 1664357990400 in words is "one trillion, six hundred sixty-four billion, three hundred fifty-seven million, nine hundred ninety thousand, four hundred".