1866275640 has 320 divisors, whose sum is σ = 6862268160. Its totient is φ = 452874240.

The previous prime is 1866275629. The next prime is 1866275647. The reversal of 1866275640 is 465726681.

1866275640 is a `hidden beast` number, since 1 + 8 + 66 + 27 + 564 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1866275647) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1706934 + ... + 1708026.

It is an arithmetic number, because the mean of its divisors is an integer number (21444588).

Almost surely, 2^1866275640 is an apocalyptic number.

1866275640 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 1866275640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3431134080).

1866275640 is an abundant number, since it is smaller than the sum of its proper divisors (4995992520).

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

1866275640 is a wasteful number, since it uses less digits than its factorization.

1866275640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1164 (or 1151 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The square root of 1866275640 is about 43200.4124980306. The cubic root of 1866275640 is about 1231.1905189471.

The spelling of 1866275640 in words is "one billion, eight hundred sixty-six million, two hundred seventy-five thousand, six hundred forty".