1989167381 has 2 divisors, whose sum is σ = 1989167382. Its totient is φ = 1989167380.

The previous prime is 1989167347. The next prime is 1989167441. The reversal of 1989167381 is 1837619891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1901744881 + 87422500 = 43609^2 + 9350^2 .

It is a cyclic number.

It is not a de Polignac number, because 1989167381 - 2¹⁴ = 1989150997 is a prime.

It is a super-2 number, since 2×1989167381² = 7913573739268798322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1989167281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994583690 + 994583691.

It is an arithmetic number, because the mean of its divisors is an integer number (994583691).

Almost surely, 2^1989167381 is an apocalyptic number.

It is an amenable number.

1989167381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1989167381 is an equidigital number, since it uses as much as digits as its factorization.

1989167381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 53.

The square root of 1989167381 is about 44600.0827465600. The cubic root of 1989167381 is about 1257.6422232019.

The spelling of 1989167381 in words is "one billion, nine hundred eighty-nine million, one hundred sixty-seven thousand, three hundred eighty-one".