1191645 has 64 divisors (see below), whose sum is σ = 2634240. Its totient is φ = 497664.

The previous prime is 1191643. The next prime is 1191667. The reversal of 1191645 is 5461911.

1191645 is a `hidden beast` number, since 1 + 19 + 1 + 645 = 666.

It is not a de Polignac number, because 1191645 - 2¹ = 1191643 is a prime.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1191643) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12237 + ... + 12333.

It is an arithmetic number, because the mean of its divisors is an integer number (41160).

2^1191645 is an apocalyptic number.

1191645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1191645 is an abundant number, since it is smaller than the sum of its proper divisors (1442595).

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

1191645 is a wasteful number, since it uses less digits than its factorization.

1191645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131 (or 125 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 1191645 is about 1091.6249355891. The cubic root of 1191645 is about 106.0186569747.

It can be divided in two parts, 119 and 1645, that added together give a square (1764 = 42²).

The spelling of 1191645 in words is "one million, one hundred ninety-one thousand, six hundred forty-five".