1661659272000 has 3136 divisors, whose sum is σ = 7916198105088. Its totient is φ = 335923200000.

The previous prime is 1661659271971. The next prime is 1661659272001. The reversal of 1661659272000 is 2729561661.

1661659272000 is a `hidden beast` number, since 1 + 6 + 616 + 5 + 9 + 2 + 7 + 20 + 0 + 0 = 666.

It is a super-2 number, since 2×1661659272000² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661659272001) by changing a digit.

It is a polite number, since it can be written in 447 ways as a sum of consecutive naturals, for example, 16452071950 + ... + 16452072050.

Almost surely, 2^{1661659272000} is an apocalyptic number.

1661659272000 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 1661659272000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3958099052544).

1661659272000 is an abundant number, since it is smaller than the sum of its proper divisors (6254538833088).

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

1661659272000 is a wasteful number, since it uses less digits than its factorization.

1661659272000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The spelling of 1661659272000 in words is "one trillion, six hundred sixty-one billion, six hundred fifty-nine million, two hundred seventy-two thousand".