1621224 has 96 divisors (see below), whose sum is σ = 5054400. Its totient is φ = 464640.

The previous prime is 1621219. The next prime is 1621231. The reversal of 1621224 is 4221261.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 1621197 and 1621206.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 18172 + ... + 18260.

It is an arithmetic number, because the mean of its divisors is an integer number (52650).

2^1621224 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1621224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2527200).

1621224 is an abundant number, since it is smaller than the sum of its proper divisors (3433176).

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

1621224 is a wasteful number, since it uses less digits than its factorization.

1621224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135 (or 128 counting only the distinct ones).

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

The square root of 1621224 is about 1273.2729479573. The cubic root of 1621224 is about 117.4756007886.

Adding to 1621224 its reverse (4221261), we get a palindrome (5842485).

The spelling of 1621224 in words is "one million, six hundred twenty-one thousand, two hundred twenty-four".