1630221 has 4 divisors (see below), whose sum is σ = 2173632. Its totient is φ = 1086812.

The previous prime is 1630199. The next prime is 1630243. The reversal of 1630221 is 1220361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (1630199) and next prime (1630243).

It is a cyclic number.

It is not a de Polignac number, because 1630221 - 2⁷ = 1630093 is a prime.

It is a D-number.

1630221 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1630221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1630261) 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, 271701 + ... + 271706.

It is an arithmetic number, because the mean of its divisors is an integer number (543408).

2^1630221 is an apocalyptic number.

It is an amenable number.

1630221 is a deficient number, since it is larger than the sum of its proper divisors (543411).

1630221 is an equidigital number, since it uses as much as digits as its factorization.

1630221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543410.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1630221 is about 1276.8010808266. The cubic root of 1630221 is about 117.6925107368.

Adding to 1630221 its reverse (1220361), we get a palindrome (2850582).

The spelling of 1630221 in words is "one million, six hundred thirty thousand, two hundred twenty-one".