1811955 has 16 divisors (see below), whose sum is σ = 2927520. Its totient is φ = 956928.

The previous prime is 1811939. The next prime is 1811959. The reversal of 1811955 is 5591181.

It is not a de Polignac number, because 1811955 - 2⁴ = 1811939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1811959) 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, 1161 + ... + 2229.

It is an arithmetic number, because the mean of its divisors is an integer number (182970).

2^1811955 is an apocalyptic number.

1811955 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1811955 is a deficient number, since it is larger than the sum of its proper divisors (1115565).

1811955 is a wasteful number, since it uses less digits than its factorization.

1811955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1190.

The product of its digits is 1800, while the sum is 30.

The square root of 1811955 is about 1346.0887786472. The cubic root of 1811955 is about 121.9127522756.

The spelling of 1811955 in words is "one million, eight hundred eleven thousand, nine hundred fifty-five".