1955820 has 48 divisors (see below), whose sum is σ = 5630688. Its totient is φ = 506880.

The previous prime is 1955819. The next prime is 1955827. The reversal of 1955820 is 285591.

1955820 = 128² + 129² + ... + 199².

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a d-powerful number, because it can be written as 1 + 9 + 5³ + 5⁹ + 8³ + 2¹¹ + 0 .

It is not an unprimeable number, because it can be changed into a prime (1955827) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1780 + ... + 2660.

It is an arithmetic number, because the mean of its divisors is an integer number (117306).

2^1955820 is an apocalyptic number.

1955820 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 1955820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2815344).

1955820 is an abundant number, since it is smaller than the sum of its proper divisors (3674868).

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

1955820 is a wasteful number, since it uses less digits than its factorization.

1955820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 930 (or 928 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 1955820 is about 1398.5063460707. The cubic root of 1955820 is about 125.0574669097.

It can be divided in two parts, 1955 and 820, that added together give a triangular number (2775 = T₇₄).

The spelling of 1955820 in words is "one million, nine hundred fifty-five thousand, eight hundred twenty".