1630021 has 2 divisors, whose sum is σ = 1630022. Its totient is φ = 1630020.

The previous prime is 1630019. The next prime is 1630049. The reversal of 1630021 is 1200361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1368900 + 261121 = 1170^2 + 511^2 .

It is an emirp because it is prime and its reverse (1200361) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1630021 - 2¹ = 1630019 is a prime.

Together with 1630019, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1629983 and 1630010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1630051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 815010 + 815011.

It is an arithmetic number, because the mean of its divisors is an integer number (815011).

2^1630021 is an apocalyptic number.

It is an amenable number.

1630021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1630021 is an equidigital number, since it uses as much as digits as its factorization.

1630021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 1630021 is about 1276.7227576886. The cubic root of 1630021 is about 117.6876975929.

Adding to 1630021 its reverse (1200361), we get a palindrome (2830382).

The spelling of 1630021 in words is "one million, six hundred thirty thousand, twenty-one".