445210021 has 4 divisors (see below), whose sum is σ = 456068844. Its totient is φ = 434351200.

The previous prime is 445210019. The next prime is 445210027. The reversal of 445210021 is 120012544.

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 167987521 + 277222500 = 12961^2 + 16650^2 .

It is a cyclic number.

It is not a de Polignac number, because 445210021 - 2¹ = 445210019 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 (445210027) 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, 5429350 + ... + 5429431.

It is an arithmetic number, because the mean of its divisors is an integer number (114017211).

Almost surely, 2^445210021 is an apocalyptic number.

445210021 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

445210021 is a deficient number, since it is larger than the sum of its proper divisors (10858823).

445210021 is a wasteful number, since it uses less digits than its factorization.

445210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10858822.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 445210021 is about 21100.0004976303. Note that the first 3 decimals coincide. The cubic root of 445210021 is about 763.5807602058.

Adding to 445210021 its reverse (120012544), we get a palindrome (565222565).

The spelling of 445210021 in words is "four hundred forty-five million, two hundred ten thousand, twenty-one".