1866240 has 140 divisors (see below), whose sum is σ = 6708834. Its totient is φ = 497664.

The previous prime is 1866239. The next prime is 1866247. The reversal of 1866240 is 426681.

It is a Jordan-Polya number, since it can be written as 6! ⋅ (3!)⁴ ⋅ 2!.

It can be written as a sum of positive squares in only one way, i.e., 1679616 + 186624 = 1296^2 + 432^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (1866247) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 373246 + ... + 373250.

2^1866240 is an apocalyptic number.

1866240 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 1866240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3354417).

1866240 is an abundant number, since it is smaller than the sum of its proper divisors (4842594).

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

1866240 is an frugal number, since it uses more digits than its factorization.

1866240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41 (or 10 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 1866240 is about 1366.1039491927. The cubic root of 1866240 is about 123.1182681607.

The spelling of 1866240 in words is "one million, eight hundred sixty-six thousand, two hundred forty".