1288399 has 4 divisors (see below), whose sum is σ = 1472464. Its totient is φ = 1104336.

The previous prime is 1288393. The next prime is 1288421. The reversal of 1288399 is 9938821.

1288399 = T₄₂₂ + T₄₂₃ + ... + T₄₃₅.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1288399 - 2⁵ = 1288367 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1288393) 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, 92022 + ... + 92035.

It is an arithmetic number, because the mean of its divisors is an integer number (368116).

2^1288399 is an apocalyptic number.

1288399 is a deficient number, since it is larger than the sum of its proper divisors (184065).

1288399 is an equidigital number, since it uses as much as digits as its factorization.

1288399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184064.

The product of its digits is 31104, while the sum is 40.

The square root of 1288399 is about 1135.0766493942. The cubic root of 1288399 is about 108.8136703826.

The spelling of 1288399 in words is "one million, two hundred eighty-eight thousand, three hundred ninety-nine".