1920389 has 4 divisors (see below), whose sum is σ = 1925580. Its totient is φ = 1915200.

The previous prime is 1920383. The next prime is 1920397. The reversal of 1920389 is 9830291.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9830291 = 181 ⋅54311.

It can be written as a sum of positive squares in 2 ways, for example, as 1119364 + 801025 = 1058^2 + 895^2 .

It is a cyclic number.

It is not a de Polignac number, because 1920389 - 2¹² = 1916293 is a prime.

It is a super-2 number, since 2×1920389² = 7375787822642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1920383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1994 + ... + 2795.

It is an arithmetic number, because the mean of its divisors is an integer number (481395).

2^1920389 is an apocalyptic number.

It is an amenable number.

1920389 is a deficient number, since it is larger than the sum of its proper divisors (5191).

1920389 is an equidigital number, since it uses as much as digits as its factorization.

1920389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5190.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 1920389 is about 1385.7810072302. The cubic root of 1920389 is about 124.2976935147.

The spelling of 1920389 in words is "one million, nine hundred twenty thousand, three hundred eighty-nine".