445581661 has 4 divisors (see below), whose sum is σ = 509236192. Its totient is φ = 381927132.

The previous prime is 445581641. The next prime is 445581671. The reversal of 445581661 is 166185544.

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 a cyclic number.

It is not a de Polignac number, because 445581661 - 2⁷ = 445581533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (445581601) 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, 31827255 + ... + 31827268.

It is an arithmetic number, because the mean of its divisors is an integer number (127309048).

Almost surely, 2^445581661 is an apocalyptic number.

It is an amenable number.

445581661 is a deficient number, since it is larger than the sum of its proper divisors (63654531).

445581661 is an equidigital number, since it uses as much as digits as its factorization.

445581661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63654530.

The product of its digits is 115200, while the sum is 40.

The square root of 445581661 is about 21108.8052954212. The cubic root of 445581661 is about 763.7931679951.

The spelling of 445581661 in words is "four hundred forty-five million, five hundred eighty-one thousand, six hundred sixty-one".