1820620 has 48 divisors (see below), whose sum is σ = 4102560. Its totient is φ = 677376.

The previous prime is 1820617. The next prime is 1820629. The reversal of 1820620 is 260281.

1820620 = T₂₂₁ + T₂₂₂ + ... + T₂₇₈.

It is a happy number.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1820629) 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 15 ways as a sum of consecutive naturals, for example, 24904 + ... + 24976.

It is an arithmetic number, because the mean of its divisors is an integer number (85470).

2^1820620 is an apocalyptic number.

1820620 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 1820620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2051280).

1820620 is an abundant number, since it is smaller than the sum of its proper divisors (2281940).

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

1820620 is a wasteful number, since it uses less digits than its factorization.

1820620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154 (or 152 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 1820620 is about 1349.3035240449. The cubic root of 1820620 is about 122.1067774313.

The spelling of 1820620 in words is "one million, eight hundred twenty thousand, six hundred twenty".