1866455989489 has 27 divisors (see below), whose sum is σ = 2351201463873. Its totient is φ = 1476658022112.

The previous prime is 1866455989471. The next prime is 1866455989523. The reversal of 1866455989489 is 9849895546681.

The square root of 1866455989489 is 1366183.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 42011471089 + 1824444518400 = 204967^2 + 1350720^2 .

It is not a de Polignac number, because 1866455989489 - 2⁹ = 1866455988977 is a prime.

It is a super-2 number, since 2×1866455989489² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1866455989589) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 124315147 + ... + 124330159.

It is an arithmetic number, because the mean of its divisors is an integer number (87081535699).

Almost surely, 2^{1866455989489} is an apocalyptic number.

1866455989489 is the 1366183-rd square number.

1866455989489 is the 683092-nd centered octagonal number.

It is an amenable number.

1866455989489 is a deficient number, since it is larger than the sum of its proper divisors (484745474384).

1866455989489 is an frugal number, since it uses more digits than its factorization.

1866455989489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30066 (or 15033 counting only the distinct ones).

The product of its digits is 5374771200, while the sum is 82.

The spelling of 1866455989489 in words is "one trillion, eight hundred sixty-six billion, four hundred fifty-five million, nine hundred eighty-nine thousand, four hundred eighty-nine".