611820 has 96 divisors (see below), whose sum is σ = 2096640. Its totient is φ = 146880.

The previous prime is 611803. The next prime is 611827. The reversal of 611820 is 28116.

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

It is a junction number, because it is equal to n+sod(n) for n = 611793 and 611802.

It is not an unprimeable number, because it can be changed into a prime (611827) by changing a digit.

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, 5889 + ... + 5991.

It is an arithmetic number, because the mean of its divisors is an integer number (21840).

2⁶¹¹⁸²⁰ is an apocalyptic number.

611820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

611820 is the 495-th heptagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 611820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1048320).

611820 is an abundant number, since it is smaller than the sum of its proper divisors (1484820).

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

611820 is a wasteful number, since it uses less digits than its factorization.

611820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 611820 is about 782.1892354156. The cubic root of 611820 is about 84.8935229610.

Adding to 611820 its reverse (28116), we get a palindrome (639936).

It can be divided in two parts, 611 and 820, that added together give a triangular number (1431 = T₅₃).

The spelling of 611820 in words is "six hundred eleven thousand, eight hundred twenty".