1801900 has 36 divisors (see below), whose sum is σ = 4024048. Its totient is φ = 699840.

The previous prime is 1801897. The next prime is 1801901. The reversal of 1801900 is 91081.

It is a super-2 number, since 2×1801900² = 6493687220000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1801901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3457 + ... + 3943.

2^1801900 is an apocalyptic number.

1801900 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 1801900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2012024).

1801900 is an abundant number, since it is smaller than the sum of its proper divisors (2222148).

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

1801900 is a wasteful number, since it uses less digits than its factorization.

1801900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 538 (or 531 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 1801900 is about 1342.3486879347. The cubic root of 1801900 is about 121.6868255415.

Adding to 1801900 its reverse (91081), we get a palindrome (1892981).

It can be divided in two parts, 1801 and 900, that multiplied together give a triangular number (1620900 = T₁₈₀₀).

The spelling of 1801900 in words is "one million, eight hundred one thousand, nine hundred".