1986397 has 4 divisors (see below), whose sum is σ = 2270176. Its totient is φ = 1702620.

The previous prime is 1986373. The next prime is 1986401. The reversal of 1986397 is 7936891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1986397 - 2¹⁵ = 1953629 is a prime.

It is a Duffinian number.

1986397 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1986337) 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, 141879 + ... + 141892.

It is an arithmetic number, because the mean of its divisors is an integer number (567544).

2^1986397 is an apocalyptic number.

It is an amenable number.

1986397 is a deficient number, since it is larger than the sum of its proper divisors (283779).

1986397 is an equidigital number, since it uses as much as digits as its factorization.

1986397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283778.

The product of its digits is 81648, while the sum is 43.

The square root of 1986397 is about 1409.3959699105. The cubic root of 1986397 is about 125.7058098255.

The spelling of 1986397 in words is "one million, nine hundred eighty-six thousand, three hundred ninety-seven".