1621818 has 24 divisors (see below), whose sum is σ = 3833856. Its totient is φ = 491400.

The previous prime is 1621793. The next prime is 1621819. The reversal of 1621818 is 8181261.

1621818 is a modest number, since divided by 1818 gives 162 as remainder.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1621791 and 1621800.

It is not an unprimeable number, because it can be changed into a prime (1621819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3898 + ... + 4293.

It is an arithmetic number, because the mean of its divisors is an integer number (159744).

2^1621818 is an apocalyptic number.

1621818 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1621818 is an abundant number, since it is smaller than the sum of its proper divisors (2212038).

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

1621818 is a wasteful number, since it uses less digits than its factorization.

1621818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8210 (or 8207 counting only the distinct ones).

The product of its digits is 768, while the sum is 27.

The square root of 1621818 is about 1273.5061837306. The cubic root of 1621818 is about 117.4899463256.

The spelling of 1621818 in words is "one million, six hundred twenty-one thousand, eight hundred eighteen".