445661 has 4 divisors (see below), whose sum is σ = 449052. Its totient is φ = 442272.

The previous prime is 445657. The next prime is 445691. The reversal of 445661 is 166544.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 383161 + 62500 = 619^2 + 250^2 .

It is a cyclic number.

It is not a de Polignac number, because 445661 - 2² = 445657 is a prime.

It is a super-2 number, since 2×445661² = 397227453842, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 445661.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1490 + ... + 1763.

It is an arithmetic number, because the mean of its divisors is an integer number (112263).

2⁴⁴⁵⁶⁶¹ is an apocalyptic number.

It is an amenable number.

445661 is a deficient number, since it is larger than the sum of its proper divisors (3391).

445661 is a wasteful number, since it uses less digits than its factorization.

445661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3390.

The product of its digits is 2880, while the sum is 26.

The square root of 445661 is about 667.5784598083. The cubic root of 445661 is about 76.3838498249.

The spelling of 445661 in words is "four hundred forty-five thousand, six hundred sixty-one".