1666042761880 has 128 divisors (see below), whose sum is σ = 4339876423680. Its totient is φ = 563792325120.

The previous prime is 1666042761857. The next prime is 1666042762037. The reversal of 1666042761880 is 881672406661.

It is a super-2 number, since 2×1666042761880² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24623857 + ... + 24691423.

It is an arithmetic number, because the mean of its divisors is an integer number (33905284560).

Almost surely, 2^{1666042761880} is an apocalyptic number.

1666042761880 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 1666042761880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2169938211840).

1666042761880 is an abundant number, since it is smaller than the sum of its proper divisors (2673833661800).

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

1666042761880 is a wasteful number, since it uses less digits than its factorization.

1666042761880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68729 (or 68725 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 55.

The spelling of 1666042761880 in words is "one trillion, six hundred sixty-six billion, forty-two million, seven hundred sixty-one thousand, eight hundred eighty".