1620780 has 96 divisors (see below), whose sum is σ = 5515776. Its totient is φ = 347136.

The previous prime is 1620769. The next prime is 1620803. The reversal of 1620780 is 870261.

It is a zygodrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 1620780.

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 31 ways as a sum of consecutive naturals, for example, 7027 + ... + 7253.

It is an arithmetic number, because the mean of its divisors is an integer number (57456).

2^1620780 is an apocalyptic number.

1620780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1620780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2757888).

1620780 is an abundant number, since it is smaller than the sum of its proper divisors (3894996).

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

1620780 is a wasteful number, since it uses less digits than its factorization.

1620780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263 (or 261 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 1620780 is about 1273.0985822001. The cubic root of 1620780 is about 117.4648755734.

The spelling of 1620780 in words is "one million, six hundred twenty thousand, seven hundred eighty".