1642221 has 16 divisors (see below), whose sum is σ = 2780800. Its totient is φ = 938304.

The previous prime is 1642211. The next prime is 1642231. The reversal of 1642221 is 1222461.

1642221 is a `hidden beast` number, since 1 + 642 + 2 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (1642211) and next prime (1642231).

It is not a de Polignac number, because 1642221 - 2⁷ = 1642093 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1642194 and 1642203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1642211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4156 + ... + 4533.

It is an arithmetic number, because the mean of its divisors is an integer number (173800).

2^1642221 is an apocalyptic number.

It is an amenable number.

1642221 is a deficient number, since it is larger than the sum of its proper divisors (1138579).

1642221 is an equidigital number, since it uses as much as digits as its factorization.

1642221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8705 (or 8699 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 1642221 is about 1281.4917089080. The cubic root of 1642221 is about 117.9805818856.

Adding to 1642221 its reverse (1222461), we get a palindrome (2864682).

The spelling of 1642221 in words is "one million, six hundred forty-two thousand, two hundred twenty-one".