1864991 has 4 divisors (see below), whose sum is σ = 1925184. Its totient is φ = 1804800.

The previous prime is 1864987. The next prime is 1865011. The reversal of 1864991 is 1994681.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1994681 = 13 ⋅153437.

It is a cyclic number.

It is not a de Polignac number, because 1864991 - 2² = 1864987 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 (1864901) 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, 30050 + ... + 30111.

It is an arithmetic number, because the mean of its divisors is an integer number (481296).

2^1864991 is an apocalyptic number.

1864991 is a deficient number, since it is larger than the sum of its proper divisors (60193).

1864991 is an equidigital number, since it uses as much as digits as its factorization.

1864991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60192.

The product of its digits is 15552, while the sum is 38.

The square root of 1864991 is about 1365.6467332367. The cubic root of 1864991 is about 123.0907959823.

The spelling of 1864991 in words is "one million, eight hundred sixty-four thousand, nine hundred ninety-one".