1661065410000 has 400 divisors, whose sum is σ = 5715926568000. Its totient is φ = 414077952000.

The previous prime is 1661065409999. The next prime is 1661065410007. The reversal of 1661065410000 is 145601661.

It is a tau number, because it is divible by the number of its divisors (400).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a self number, because there is not a number n which added to its sum of digits gives 1661065410000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661065410007) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 75979071 + ... + 76000929.

It is an arithmetic number, because the mean of its divisors is an integer number (14289816420).

Almost surely, 2^{1661065410000} is an apocalyptic number.

1661065410000 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 1661065410000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2857963284000).

1661065410000 is an abundant number, since it is smaller than the sum of its proper divisors (4054861158000).

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

1661065410000 is a wasteful number, since it uses less digits than its factorization.

1661065410000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22056 (or 22035 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The spelling of 1661065410000 in words is "one trillion, six hundred sixty-one billion, sixty-five million, four hundred ten thousand".