1581066 has 64 divisors (see below), whose sum is σ = 3916800. Its totient is φ = 470448.

The previous prime is 1581061. The next prime is 1581071. The reversal of 1581066 is 6601851.

It is an interprime number because it is at equal distance from previous prime (1581061) and next prime (1581071).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1581061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23565 + ... + 23631.

It is an arithmetic number, because the mean of its divisors is an integer number (61200).

2^1581066 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1581066, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1958400).

1581066 is an abundant number, since it is smaller than the sum of its proper divisors (2335734).

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

1581066 is a wasteful number, since it uses less digits than its factorization.

1581066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 1581066 is about 1257.4044695324. The cubic root of 1581066 is about 116.4975163254.

It can be divided in two parts, 15810 and 66, that added together give a square (15876 = 126²).

The spelling of 1581066 in words is "one million, five hundred eighty-one thousand, sixty-six".