447989021 has 2 divisors, whose sum is σ = 447989022. Its totient is φ = 447989020.

The previous prime is 447988993. The next prime is 447989051. The reversal of 447989021 is 120989744.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 443944900 + 4044121 = 21070^2 + 2011^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-447989021 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (447989051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 223994510 + 223994511.

It is an arithmetic number, because the mean of its divisors is an integer number (223994511).

Almost surely, 2^447989021 is an apocalyptic number.

It is an amenable number.

447989021 is a deficient number, since it is larger than the sum of its proper divisors (1).

447989021 is an equidigital number, since it uses as much as digits as its factorization.

447989021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 447989021 is about 21165.7511324309. The cubic root of 447989021 is about 765.1662224414.

The spelling of 447989021 in words is "four hundred forty-seven million, nine hundred eighty-nine thousand, twenty-one".