444745921 has 3 divisors (see below), whose sum is σ = 444767011. Its totient is φ = 444724832.

The previous prime is 444745867. The next prime is 444745927. The reversal of 444745921 is 129547444.

The square root of 444745921 is 21089.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 439363521 + 5382400 = 20961^2 + 2320^2 .

It is not a de Polignac number, because 444745921 - 2⁷ = 444745793 is a prime.

It is a super-2 number, since 2×444745921² = 395597868492276482, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (444745927) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 10545 + ... + 31633.

Almost surely, 2^444745921 is an apocalyptic number.

444745921 is the 21089-th square number.

444745921 is the 10545-th centered octagonal number.

It is an amenable number.

444745921 is a deficient number, since it is larger than the sum of its proper divisors (21090).

444745921 is an frugal number, since it uses more digits than its factorization.

444745921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42178 (or 21089 counting only the distinct ones).

The product of its digits is 161280, while the sum is 40.

The cubic root of 444745921 is about 763.3153416217.

The spelling of 444745921 in words is "four hundred forty-four million, seven hundred forty-five thousand, nine hundred twenty-one".