1663664047920 has 800 divisors, whose sum is σ = 6965841062400. Its totient is φ = 359491571712.

The previous prime is 1663664047841. The next prime is 1663664047961. The reversal of 1663664047920 is 297404663661.

It is a happy number.

1663664047920 is a `hidden beast` number, since 1 + 66 + 36 + 64 + 0 + 479 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 471424716 + ... + 471428244.

It is an arithmetic number, because the mean of its divisors is an integer number (8707301328).

Almost surely, 2^{1663664047920} is an apocalyptic number.

1663664047920 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 1663664047920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3482920531200).

1663664047920 is an abundant number, since it is smaller than the sum of its proper divisors (5302177014480).

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

1663664047920 is a wasteful number, since it uses less digits than its factorization.

1663664047920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4127 (or 4112 counting only the distinct ones).

The product of its (nonzero) digits is 7838208, while the sum is 54.

The spelling of 1663664047920 in words is "one trillion, six hundred sixty-three billion, six hundred sixty-four million, forty-seven thousand, nine hundred twenty".