1191901 has 4 divisors (see below), whose sum is σ = 1203804. Its totient is φ = 1180000.

The previous prime is 1191899. The next prime is 1191923. The reversal of 1191901 is 1091911.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 940900 + 251001 = 970^2 + 501^2 .

It is a cyclic number.

It is not a de Polignac number, because 1191901 - 2¹ = 1191899 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1191941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5800 + ... + 6001.

It is an arithmetic number, because the mean of its divisors is an integer number (300951).

2^1191901 is an apocalyptic number.

It is an amenable number.

1191901 is a deficient number, since it is larger than the sum of its proper divisors (11903).

1191901 is a wasteful number, since it uses less digits than its factorization.

1191901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11902.

The product of its (nonzero) digits is 81, while the sum is 22.

The square root of 1191901 is about 1091.7421856830. The cubic root of 1191901 is about 106.0262483946.

The spelling of 1191901 in words is "one million, one hundred ninety-one thousand, nine hundred one".