1288731 has 8 divisors (see below), whose sum is σ = 1777680. Its totient is φ = 829472.

The previous prime is 1288711. The next prime is 1288733. The reversal of 1288731 is 1378821.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1288731 - 2⁵ = 1288699 is a prime.

It is a super-2 number, since 2×1288731² = 3321655180722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1288733) 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 7 ways as a sum of consecutive naturals, for example, 7320 + ... + 7493.

It is an arithmetic number, because the mean of its divisors is an integer number (222210).

2^1288731 is an apocalyptic number.

1288731 is a deficient number, since it is larger than the sum of its proper divisors (488949).

1288731 is a wasteful number, since it uses less digits than its factorization.

1288731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14845.

The product of its digits is 2688, while the sum is 30.

The square root of 1288731 is about 1135.2228856044. Note that the first 3 decimals coincide. The cubic root of 1288731 is about 108.8230160992.

The spelling of 1288731 in words is "one million, two hundred eighty-eight thousand, seven hundred thirty-one".