1821181065 has 32 divisors (see below), whose sum is σ = 3346099200. Its totient is φ = 836521920.

The previous prime is 1821181039. The next prime is 1821181067. The reversal of 1821181065 is 5601811281.

It is not a de Polignac number, because 1821181065 - 2¹⁶ = 1821115529 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1821181067) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 287325 + ... + 293594.

It is an arithmetic number, because the mean of its divisors is an integer number (104565600).

Almost surely, 2^1821181065 is an apocalyptic number.

1821181065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1821181065 is a deficient number, since it is larger than the sum of its proper divisors (1524918135).

1821181065 is a wasteful number, since it uses less digits than its factorization.

1821181065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580957.

The product of its (nonzero) digits is 3840, while the sum is 33.

The square root of 1821181065 is about 42675.2980657429. The cubic root of 1821181065 is about 1221.1931945961.

The spelling of 1821181065 in words is "one billion, eight hundred twenty-one million, one hundred eighty-one thousand, sixty-five".