1531686 has 32 divisors (see below), whose sum is σ = 3356640. Its totient is φ = 463104.

The previous prime is 1531681. The next prime is 1531697. The reversal of 1531686 is 6861351.

Its product of digits (4320) is a multiple of the sum of its prime divisors (360).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1531681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5560 + ... + 5828.

It is an arithmetic number, because the mean of its divisors is an integer number (104895).

2^1531686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1531686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1678320).

1531686 is an abundant number, since it is smaller than the sum of its proper divisors (1824954).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1531686 is a wasteful number, since it uses less digits than its factorization.

1531686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360.

The product of its digits is 4320, while the sum is 30.

The square root of 1531686 is about 1237.6130251415. The cubic root of 1531686 is about 115.2718458564.

The spelling of 1531686 in words is "one million, five hundred thirty-one thousand, six hundred eighty-six".