1820816969 has 2 divisors, whose sum is σ = 1820816970. Its totient is φ = 1820816968.

The previous prime is 1820816923. The next prime is 1820816981. The reversal of 1820816969 is 9696180281.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1807950400 + 12866569 = 42520^2 + 3587^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1820816969 is a prime.

It is a super-2 number, since 2×1820816969² = 6630748869196693922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1820810969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910408484 + 910408485.

It is an arithmetic number, because the mean of its divisors is an integer number (910408485).

Almost surely, 2^1820816969 is an apocalyptic number.

It is an amenable number.

1820816969 is a deficient number, since it is larger than the sum of its proper divisors (1).

1820816969 is an equidigital number, since it uses as much as digits as its factorization.

1820816969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 373248, while the sum is 50.

The square root of 1820816969 is about 42671.0319654915. The cubic root of 1820816969 is about 1221.1118076324. Note that the first 3 decimals are identical.

The spelling of 1820816969 in words is "one billion, eight hundred twenty million, eight hundred sixteen thousand, nine hundred sixty-nine".