1662399 has 6 divisors (see below), whose sum is σ = 2401256. Its totient is φ = 1108260.

The previous prime is 1662389. The next prime is 1662403. The reversal of 1662399 is 9932661.

It is not a de Polignac number, because 1662399 - 2⁴ = 1662383 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 (1662319) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 92347 + ... + 92364.

2^1662399 is an apocalyptic number.

1662399 is a deficient number, since it is larger than the sum of its proper divisors (738857).

1662399 is a wasteful number, since it uses less digits than its factorization.

1662399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184717 (or 184714 counting only the distinct ones).

The product of its digits is 17496, while the sum is 36.

The square root of 1662399 is about 1289.3405291078. The cubic root of 1662399 is about 118.4618260845.

The spelling of 1662399 in words is "one million, six hundred sixty-two thousand, three hundred ninety-nine".