1801090 has 16 divisors (see below), whose sum is σ = 3260088. Its totient is φ = 716416.

The previous prime is 1801073. The next prime is 1801091. The reversal of 1801090 is 901081.

It can be written as a sum of positive squares in 4 ways, for example, as 717409 + 1083681 = 847^2 + 1041^2 .

It is not an unprimeable number, because it can be changed into a prime (1801091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1944 + ... + 2716.

2^1801090 is an apocalyptic number.

1801090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1801090 is a deficient number, since it is larger than the sum of its proper divisors (1458998).

1801090 is a wasteful number, since it uses less digits than its factorization.

1801090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1013.

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

The square root of 1801090 is about 1342.0469440374. The cubic root of 1801090 is about 121.6685890316.

Subtracting from 1801090 its reverse (901081), we obtain a palindrome (900009).

It can be divided in two parts, 18010 and 90, that multiplied together give a triangular number (1620900 = T₁₈₀₀).

The spelling of 1801090 in words is "one million, eight hundred one thousand, ninety".