1669221 has 16 divisors (see below), whose sum is σ = 2493120. Its totient is φ = 1103760.

The previous prime is 1669219. The next prime is 1669223. The reversal of 1669221 is 1229661.

It is an interprime number because it is at equal distance from previous prime (1669219) and next prime (1669223).

It is not a de Polignac number, because 1669221 - 2¹ = 1669219 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1669223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5551 + ... + 5843.

It is an arithmetic number, because the mean of its divisors is an integer number (155820).

2^1669221 is an apocalyptic number.

It is an amenable number.

1669221 is a deficient number, since it is larger than the sum of its proper divisors (823899).

1669221 is a wasteful number, since it uses less digits than its factorization.

1669221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513 (or 507 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 1669221 is about 1291.9833590260. The cubic root of 1669221 is about 118.6236491737.

The spelling of 1669221 in words is "one million, six hundred sixty-nine thousand, two hundred twenty-one".