1989397 has 4 divisors (see below), whose sum is σ = 2009196. Its totient is φ = 1969600.

The previous prime is 1989353. The next prime is 1989401. The reversal of 1989397 is 7939891.

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 1168561 + 820836 = 1081^2 + 906^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1989397 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 (1989307) 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, 9748 + ... + 9949.

It is an arithmetic number, because the mean of its divisors is an integer number (502299).

2^1989397 is an apocalyptic number.

It is an amenable number.

1989397 is a deficient number, since it is larger than the sum of its proper divisors (19799).

1989397 is a wasteful number, since it uses less digits than its factorization.

1989397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19798.

The product of its digits is 122472, while the sum is 46.

The square root of 1989397 is about 1410.4598540901. The cubic root of 1989397 is about 125.7690613204.

The spelling of 1989397 in words is "one million, nine hundred eighty-nine thousand, three hundred ninety-seven".