1866855340 has 96 divisors (see below), whose sum is σ = 4897234944. Its totient is φ = 582958080.

The previous prime is 1866855311. The next prime is 1866855349. The reversal of 1866855340 is 435586681.

It is not an unprimeable number, because it can be changed into a prime (1866855349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 61129 + ... + 86431.

It is an arithmetic number, because the mean of its divisors is an integer number (51012864).

Almost surely, 2^1866855340 is an apocalyptic number.

1866855340 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 1866855340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2448617472).

1866855340 is an abundant number, since it is smaller than the sum of its proper divisors (3030379604).

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

1866855340 is a wasteful number, since it uses less digits than its factorization.

1866855340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25367 (or 25365 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 46.

The square root of 1866855340 is about 43207.1214037686. The cubic root of 1866855340 is about 1231.3179826584.

The spelling of 1866855340 in words is "one billion, eight hundred sixty-six million, eight hundred fifty-five thousand, three hundred forty".