1665764493120 has 672 divisors, whose sum is σ = 7077144372480. Its totient is φ = 350191779840.

The previous prime is 1665764493109. The next prime is 1665764493143. The reversal of 1665764493120 is 213944675661.

It is a happy number.

1665764493120 is a `hidden beast` number, since 1 + 6 + 6 + 5 + 76 + 449 + 3 + 120 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 73633171 + ... + 73655789.

It is an arithmetic number, because the mean of its divisors is an integer number (10531464840).

Almost surely, 2^{1665764493120} is an apocalyptic number.

1665764493120 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 1665764493120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3538572186240).

1665764493120 is an abundant number, since it is smaller than the sum of its proper divisors (5411379879360).

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

1665764493120 is a wasteful number, since it uses less digits than its factorization.

1665764493120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22943 (or 22930 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 54.

The spelling of 1665764493120 in words is "one trillion, six hundred sixty-five billion, seven hundred sixty-four million, four hundred ninety-three thousand, one hundred twenty".