445581 has 10 divisors (see below), whose sum is σ = 665742. Its totient is φ = 297000.

The previous prime is 445573. The next prime is 445583. The reversal of 445581 is 185544.

It can be written as a sum of positive squares in only one way, i.e., 443556 + 2025 = 666^2 + 45^2 .

It is not a de Polignac number, because 445581 - 2³ = 445573 is a prime.

It is a super-2 number, since 2×445581² = 397084855122, which contains 22 as substring.

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

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (445583) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 2670 + ... + 2831.

2⁴⁴⁵⁵⁸¹ is an apocalyptic number.

It is an amenable number.

445581 is a deficient number, since it is larger than the sum of its proper divisors (220161).

445581 is an equidigital number, since it uses as much as digits as its factorization.

445581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5513 (or 5504 counting only the distinct ones).

The product of its digits is 3200, while the sum is 27.

The square root of 445581 is about 667.5185390684. The cubic root of 445581 is about 76.3792790311.

It can be divided in two parts, 44 and 5581, that added together give a square (5625 = 75²).

The spelling of 445581 in words is "four hundred forty-five thousand, five hundred eighty-one".