1620624 has 40 divisors (see below), whose sum is σ = 4409440. Its totient is φ = 511488.

The previous prime is 1620617. The next prime is 1620629. The reversal of 1620624 is 4260261.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1620624.

It is not an unprimeable number, because it can be changed into a prime (1620629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24 + ... + 1800.

It is an arithmetic number, because the mean of its divisors is an integer number (110236).

2^1620624 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 1620624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2204720).

1620624 is an abundant number, since it is smaller than the sum of its proper divisors (2788816).

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

1620624 is a wasteful number, since it uses less digits than its factorization.

1620624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1807 (or 1801 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 1620624 is about 1273.0373128860. The cubic root of 1620624 is about 117.4611067895.

Adding to 1620624 its reverse (4260261), we get a palindrome (5880885).

The spelling of 1620624 in words is "one million, six hundred twenty thousand, six hundred twenty-four".