1964191 has 4 divisors (see below), whose sum is σ = 2027584. Its totient is φ = 1900800.

The previous prime is 1964189. The next prime is 1964203. The reversal of 1964191 is 1914691.

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

It is a cyclic number.

It is not a de Polignac number, because 1964191 - 2¹ = 1964189 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 63361 = 1964191 / (1 + 9 + 6 + 4 + 1 + 9 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1964101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31650 + ... + 31711.

It is an arithmetic number, because the mean of its divisors is an integer number (506896).

2^1964191 is an apocalyptic number.

1964191 is a deficient number, since it is larger than the sum of its proper divisors (63393).

1964191 is an equidigital number, since it uses as much as digits as its factorization.

1964191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63392.

The product of its digits is 1944, while the sum is 31.

The square root of 1964191 is about 1401.4959864373. The cubic root of 1964191 is about 125.2356302148.

The spelling of 1964191 in words is "one million, nine hundred sixty-four thousand, one hundred ninety-one".