1661844064000 has 72 divisors (see below), whose sum is σ = 4139861373648. Its totient is φ = 664737612800.

The previous prime is 1661844063959. The next prime is 1661844064031. The reversal of 1661844064000 is 4604481661.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25934314 + ... + 25998313.

It is an arithmetic number, because the mean of its divisors is an integer number (57498074634).

Almost surely, 2^{1661844064000} is an apocalyptic number.

1661844064000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661844064000 is an abundant number, since it is smaller than the sum of its proper divisors (2478017309648).

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

1661844064000 is an frugal number, since it uses more digits than its factorization.

1661844064000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51932658 (or 51932634 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 40.

The spelling of 1661844064000 in words is "one trillion, six hundred sixty-one billion, eight hundred forty-four million, sixty-four thousand".