1621218 has 16 divisors (see below), whose sum is σ = 3312000. Its totient is φ = 528816.

The previous prime is 1621177. The next prime is 1621219. The reversal of 1621218 is 8121261.

It is a junction number, because it is equal to n+sod(n) for n = 1621194 and 1621203.

It is not an unprimeable number, because it can be changed into a prime (1621219) 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 7 ways as a sum of consecutive naturals, for example, 2593 + ... + 3156.

It is an arithmetic number, because the mean of its divisors is an integer number (207000).

2^1621218 is an apocalyptic number.

1621218 is an abundant number, since it is smaller than the sum of its proper divisors (1690782).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1621218 is a wasteful number, since it uses less digits than its factorization.

1621218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5801.

The product of its digits is 192, while the sum is 21.

The square root of 1621218 is about 1273.2705918225. The cubic root of 1621218 is about 117.4754558663.

Adding to 1621218 its reverse (8121261), we get a palindrome (9742479).

The spelling of 1621218 in words is "one million, six hundred twenty-one thousand, two hundred eighteen".