1812957109 has 2 divisors, whose sum is σ = 1812957110. Its totient is φ = 1812957108.

The previous prime is 1812957101. The next prime is 1812957121. The reversal of 1812957109 is 9017592181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1653642225 + 159314884 = 40665^2 + 12622^2 .

It is a cyclic number.

It is not a de Polignac number, because 1812957109 - 2³ = 1812957101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1812957101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 906478554 + 906478555.

It is an arithmetic number, because the mean of its divisors is an integer number (906478555).

Almost surely, 2^1812957109 is an apocalyptic number.

It is an amenable number.

1812957109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1812957109 is an equidigital number, since it uses as much as digits as its factorization.

1812957109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 43.

The square root of 1812957109 is about 42578.8340493255. The cubic root of 1812957109 is about 1219.3522291297.

The spelling of 1812957109 in words is "one billion, eight hundred twelve million, nine hundred fifty-seven thousand, one hundred nine".