1838520989 has 2 divisors, whose sum is σ = 1838520990. Its totient is φ = 1838520988.

The previous prime is 1838520967. The next prime is 1838520991. The reversal of 1838520989 is 9890258381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1092302500 + 746218489 = 33050^2 + 27317^2 .

It is an emirp because it is prime and its reverse (9890258381) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1838520989 is a prime.

Together with 1838520991, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1838520989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1838520919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 919260494 + 919260495.

It is an arithmetic number, because the mean of its divisors is an integer number (919260495).

Almost surely, 2^1838520989 is an apocalyptic number.

It is an amenable number.

1838520989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1838520989 is an equidigital number, since it uses as much as digits as its factorization.

1838520989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1244160, while the sum is 53.

The square root of 1838520989 is about 42877.9779024151. The cubic root of 1838520989 is about 1225.0567212942.

The spelling of 1838520989 in words is "one billion, eight hundred thirty-eight million, five hundred twenty thousand, nine hundred eighty-nine".