1666530576778 has 16 divisors (see below), whose sum is σ = 2511256398336. Its totient is φ = 829445857200.

The previous prime is 1666530576773. The next prime is 1666530576797. The reversal of 1666530576778 is 8776750356661.

It is a super-2 number, since 2×1666530576778² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1666530576773) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4412875 + ... + 4775617.

It is an arithmetic number, because the mean of its divisors is an integer number (156953524896).

Almost surely, 2^{1666530576778} is an apocalyptic number.

1666530576778 is a deficient number, since it is larger than the sum of its proper divisors (844725821558).

1666530576778 is a wasteful number, since it uses less digits than its factorization.

1666530576778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373269.

The product of its (nonzero) digits is 266716800, while the sum is 67.

The spelling of 1666530576778 in words is "one trillion, six hundred sixty-six billion, five hundred thirty million, five hundred seventy-six thousand, seven hundred seventy-eight".