1620218 has 4 divisors (see below), whose sum is σ = 2430330. Its totient is φ = 810108.

The previous prime is 1620217. The next prime is 1620233. The reversal of 1620218 is 8120261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8120261 = 29 ⋅280009.

It can be written as a sum of positive squares in only one way, i.e., 1481089 + 139129 = 1217^2 + 373^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1620218.

It is not an unprimeable number, because it can be changed into a prime (1620217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405053 + ... + 405056.

2^1620218 is an apocalyptic number.

1620218 is a deficient number, since it is larger than the sum of its proper divisors (810112).

1620218 is an equidigital number, since it uses as much as digits as its factorization.

1620218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810111.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 1620218 is about 1272.8778417429. The cubic root of 1620218 is about 117.4512971540.

Adding to 1620218 its reverse (8120261), we get a palindrome (9740479).

The spelling of 1620218 in words is "one million, six hundred twenty thousand, two hundred eighteen".