1812820369 has 2 divisors, whose sum is σ = 1812820370. Its totient is φ = 1812820368.

The previous prime is 1812820357. The next prime is 1812820379. The reversal of 1812820369 is 9630282181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1790305344 + 22515025 = 42312^2 + 4745^2 .

It is a cyclic number.

It is not a de Polignac number, because 1812820369 - 2¹⁷ = 1812689297 is a prime.

It is a super-2 number, since 2×1812820369² = 6572635380522592322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1812820309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 906410184 + 906410185.

It is an arithmetic number, because the mean of its divisors is an integer number (906410185).

Almost surely, 2^1812820369 is an apocalyptic number.

It is an amenable number.

1812820369 is a deficient number, since it is larger than the sum of its proper divisors (1).

1812820369 is an equidigital number, since it uses as much as digits as its factorization.

1812820369 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 1812820369 is about 42577.2282916584. The cubic root of 1812820369 is about 1219.3215723250.

The spelling of 1812820369 in words is "one billion, eight hundred twelve million, eight hundred twenty thousand, three hundred sixty-nine".