445164721 has 4 divisors (see below), whose sum is σ = 445233652. Its totient is φ = 445095792.

The previous prime is 445164679. The next prime is 445164787. The reversal of 445164721 is 127461544.

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 197543025 + 247621696 = 14055^2 + 15736^2 .

It is a cyclic number.

It is not a de Polignac number, because 445164721 - 2²⁵ = 411610289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (445164121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23646 + ... + 38071.

It is an arithmetic number, because the mean of its divisors is an integer number (111308413).

Almost surely, 2^445164721 is an apocalyptic number.

It is an amenable number.

445164721 is a deficient number, since it is larger than the sum of its proper divisors (68931).

445164721 is an equidigital number, since it uses as much as digits as its factorization.

445164721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68930.

The product of its digits is 26880, while the sum is 34.

The square root of 445164721 is about 21098.9270106326. The cubic root of 445164721 is about 763.5548612816.

The spelling of 445164721 in words is "four hundred forty-five million, one hundred sixty-four thousand, seven hundred twenty-one".