389691989 has 2 divisors, whose sum is σ = 389691990. Its totient is φ = 389691988.

The previous prime is 389691947. The next prime is 389691997. The reversal of 389691989 is 989196983.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 326091364 + 63600625 = 18058^2 + 7975^2 .

It is a cyclic number.

It is not a de Polignac number, because 389691989 - 2¹⁶ = 389626453 is a prime.

It is a super-2 number, since 2×389691989² = 303719692581552242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (389291989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194845994 + 194845995.

It is an arithmetic number, because the mean of its divisors is an integer number (194845995).

Almost surely, 2^389691989 is an apocalyptic number.

It is an amenable number.

389691989 is a deficient number, since it is larger than the sum of its proper divisors (1).

389691989 is an equidigital number, since it uses as much as digits as its factorization.

389691989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7558272, while the sum is 62.

The square root of 389691989 is about 19740.6177461598. The cubic root of 389691989 is about 730.4219672118.

The spelling of 389691989 in words is "three hundred eighty-nine million, six hundred ninety-one thousand, nine hundred eighty-nine".