1666522756404 has 192 divisors, whose sum is σ = 4920513454080. Its totient is φ = 482835450240.

The previous prime is 1666522756403. The next prime is 1666522756489. The reversal of 1666522756404 is 4046572256661.

It is a super-2 number, since 2×1666522756404² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666522756403) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 67669237 + ... + 67693859.

It is an arithmetic number, because the mean of its divisors is an integer number (25627674240).

Almost surely, 2^{1666522756404} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666522756404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2460256727040).

1666522756404 is an abundant number, since it is smaller than the sum of its proper divisors (3253990697676).

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

1666522756404 is a wasteful number, since it uses less digits than its factorization.

1666522756404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27147 (or 27139 counting only the distinct ones).

The product of its (nonzero) digits is 14515200, while the sum is 54.

The spelling of 1666522756404 in words is "one trillion, six hundred sixty-six billion, five hundred twenty-two million, seven hundred fifty-six thousand, four hundred four".