1155780666 has 48 divisors (see below), whose sum is σ = 2707945344. Its totient is φ = 354878592.

The previous prime is 1155780623. The next prime is 1155780667. The reversal of 1155780666 is 6660875511.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1155780667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25800 + ... + 54563.

It is an arithmetic number, because the mean of its divisors is an integer number (56415528).

Almost surely, 2^1155780666 is an apocalyptic number.

1155780666 is an abundant number, since it is smaller than the sum of its proper divisors (1552164678).

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

1155780666 is a wasteful number, since it uses less digits than its factorization.

1155780666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80435 (or 80432 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The square root of 1155780666 is about 33996.7743469877. The cubic root of 1155780666 is about 1049.4420818336.

The spelling of 1155780666 in words is "one billion, one hundred fifty-five million, seven hundred eighty thousand, six hundred sixty-six".