1187720 has 32 divisors (see below), whose sum is σ = 2790720. Its totient is φ = 454080.

The previous prime is 1187717. The next prime is 1187723. The reversal of 1187720 is 277811.

It is an interprime number because it is at equal distance from previous prime (1187717) and next prime (1187723).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1187720.

It is not an unprimeable number, because it can be changed into a prime (1187723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 275 + ... + 1565.

It is an arithmetic number, because the mean of its divisors is an integer number (87210).

2^1187720 is an apocalyptic number.

1187720 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 1187720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1395360).

1187720 is an abundant number, since it is smaller than the sum of its proper divisors (1603000).

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

1187720 is a wasteful number, since it uses less digits than its factorization.

1187720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1325 (or 1321 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 26.

The square root of 1187720 is about 1089.8256741333. The cubic root of 1187720 is about 105.9021287197.

Subtracting from 1187720 its reverse (277811), we obtain a palindrome (909909).

The spelling of 1187720 in words is "one million, one hundred eighty-seven thousand, seven hundred twenty".