1191861 has 16 divisors (see below), whose sum is σ = 1926720. Its totient is φ = 722160.

The previous prime is 1191847. The next prime is 1191899. The reversal of 1191861 is 1681911.

It is not a de Polignac number, because 1191861 - 2¹⁰ = 1190837 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1191821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1710 + ... + 2303.

It is an arithmetic number, because the mean of its divisors is an integer number (120420).

2^1191861 is an apocalyptic number.

1191861 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1191861 is a deficient number, since it is larger than the sum of its proper divisors (734859).

1191861 is a wasteful number, since it uses less digits than its factorization.

1191861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4033 (or 4027 counting only the distinct ones).

The product of its digits is 432, while the sum is 27.

The square root of 1191861 is about 1091.7238661860. The cubic root of 1191861 is about 106.0250623069.

The spelling of 1191861 in words is "one million, one hundred ninety-one thousand, eight hundred sixty-one".