1661552745600 has 768 divisors, whose sum is σ = 6425506776960. Its totient is φ = 372867072000.

The previous prime is 1661552745581. The next prime is 1661552745659. The reversal of 1661552745600 is 65472551661.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 1661552745600.

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, 109499614 + ... + 109514786.

Almost surely, 2^{1661552745600} is an apocalyptic number.

1661552745600 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 1661552745600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3212753388480).

1661552745600 is an abundant number, since it is smaller than the sum of its proper divisors (4763954031360).

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

1661552745600 is a wasteful number, since it uses less digits than its factorization.

1661552745600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15289 (or 15272 counting only the distinct ones).

The product of its (nonzero) digits is 1512000, while the sum is 48.

The spelling of 1661552745600 in words is "one trillion, six hundred sixty-one billion, five hundred fifty-two million, seven hundred forty-five thousand, six hundred".