445681 has 4 divisors (see below), whose sum is σ = 450112. Its totient is φ = 441252.

The previous prime is 445657. The next prime is 445691. The reversal of 445681 is 186544.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 445681 - 2⁵ = 445649 is a prime.

It is a super-2 number, since 2×445681² = 397263107522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (445631) 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 3 ways as a sum of consecutive naturals, for example, 2061 + ... + 2266.

It is an arithmetic number, because the mean of its divisors is an integer number (112528).

2⁴⁴⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

445681 is a deficient number, since it is larger than the sum of its proper divisors (4431).

445681 is a wasteful number, since it uses less digits than its factorization.

445681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4430.

The product of its digits is 3840, while the sum is 28.

The square root of 445681 is about 667.5934391529. The cubic root of 445681 is about 76.3849924379.

The spelling of 445681 in words is "four hundred forty-five thousand, six hundred eighty-one".