1820001091 has 2 divisors, whose sum is σ = 1820001092. Its totient is φ = 1820001090.

The previous prime is 1820001083. The next prime is 1820001121. The reversal of 1820001091 is 1901000281.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1820001091 - 2³ = 1820001083 is a prime.

It is not a weakly prime, because it can be changed into another prime (1820001031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910000545 + 910000546.

It is an arithmetic number, because the mean of its divisors is an integer number (910000546).

Almost surely, 2^1820001091 is an apocalyptic number.

1820001091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1820001091 is an equidigital number, since it uses as much as digits as its factorization.

1820001091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 1820001091 is about 42661.4708021184. The cubic root of 1820001091 is about 1220.9293937090.

The spelling of 1820001091 in words is "one billion, eight hundred twenty million, one thousand, ninety-one".