1187840 has 56 divisors (see below), whose sum is σ = 2948940. Its totient is φ = 458752.

The previous prime is 1187839. The next prime is 1187863. The reversal of 1187840 is 487811.

It can be written as a sum of positive squares in 2 ways, for example, as 1183744 + 4096 = 1088^2 + 64^2 .

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a nialpdrome in base 8.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (3) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40946 + ... + 40974.

2^1187840 is an apocalyptic number.

1187840 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 1187840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1474470).

1187840 is an abundant number, since it is smaller than the sum of its proper divisors (1761100).

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

1187840 is an frugal number, since it uses more digits than its factorization.

1187840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60 (or 36 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 29.

The square root of 1187840 is about 1089.8807274193. The cubic root of 1187840 is about 105.9056951684.

Subtracting from 1187840 its sum of digits (29), we obtain a palindrome (1187811).

The spelling of 1187840 in words is "one million, one hundred eighty-seven thousand, eight hundred forty".