1531816 has 48 divisors (see below), whose sum is σ = 3425760. Its totient is φ = 636480.

The previous prime is 1531813. The next prime is 1531843. The reversal of 1531816 is 6181351.

It is not an unprimeable number, because it can be changed into a prime (1531811) 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 11 ways as a sum of consecutive naturals, for example, 14821 + ... + 14923.

It is an arithmetic number, because the mean of its divisors is an integer number (71370).

2^1531816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1531816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1712880).

1531816 is an abundant number, since it is smaller than the sum of its proper divisors (1893944).

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

1531816 is a wasteful number, since it uses less digits than its factorization.

1531816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146 (or 129 counting only the distinct ones).

The product of its digits is 720, while the sum is 25.

The square root of 1531816 is about 1237.6655444828. The cubic root of 1531816 is about 115.2751069504.

The spelling of 1531816 in words is "one million, five hundred thirty-one thousand, eight hundred sixteen".