1900820 has 24 divisors (see below), whose sum is σ = 4035528. Its totient is φ = 752000.

The previous prime is 1900813. The next prime is 1900831. The reversal of 1900820 is 280091.

It can be written as a sum of positive squares in 4 ways, for example, as 743044 + 1157776 = 862^2 + 1076^2 .

It is a super-2 number, since 2×1900820² = 7226233344800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1900792 and 1900801.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1550 + ... + 2490.

It is an arithmetic number, because the mean of its divisors is an integer number (168147).

2^1900820 is an apocalyptic number.

1900820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1900820 is an abundant number, since it is smaller than the sum of its proper divisors (2134708).

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

1900820 is a wasteful number, since it uses less digits than its factorization.

1900820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1051 (or 1049 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 1900820 is about 1378.7022883857. The cubic root of 1900820 is about 123.8740483146.

The spelling of 1900820 in words is "one million, nine hundred thousand, eight hundred twenty".