1820398669 has 2 divisors, whose sum is σ = 1820398670. Its totient is φ = 1820398668.

The previous prime is 1820398667. The next prime is 1820398747. The reversal of 1820398669 is 9668930281.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1471643044 + 348755625 = 38362^2 + 18675^2 .

It is a cyclic number.

It is not a de Polignac number, because 1820398669 - 2¹ = 1820398667 is a prime.

It is a super-2 number, since 2×1820398669² = 6627702628193943122, which contains 22 as substring.

Together with 1820398667, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1820398667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910199334 + 910199335.

It is an arithmetic number, because the mean of its divisors is an integer number (910199335).

Almost surely, 2^1820398669 is an apocalyptic number.

It is an amenable number.

1820398669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1820398669 is an equidigital number, since it uses as much as digits as its factorization.

1820398669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1119744, while the sum is 52.

The square root of 1820398669 is about 42666.1302323049. The cubic root of 1820398669 is about 1221.0182909679.

The spelling of 1820398669 in words is "one billion, eight hundred twenty million, three hundred ninety-eight thousand, six hundred sixty-nine".