165261389 has 2 divisors, whose sum is σ = 165261390. Its totient is φ = 165261388.

The previous prime is 165261377. The next prime is 165261457. The reversal of 165261389 is 983162561.

165261389 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126945289 + 38316100 = 11267^2 + 6190^2 .

It is a cyclic number.

It is not a de Polignac number, because 165261389 - 2¹² = 165257293 is a prime.

It is a super-2 number, since 2×165261389² = 54622653388418642, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165261359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82630694 + 82630695.

It is an arithmetic number, because the mean of its divisors is an integer number (82630695).

Almost surely, 2^165261389 is an apocalyptic number.

It is an amenable number.

165261389 is a deficient number, since it is larger than the sum of its proper divisors (1).

165261389 is an equidigital number, since it uses as much as digits as its factorization.

165261389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 41.

The square root of 165261389 is about 12855.4031053095. The cubic root of 165261389 is about 548.7701323553.

The spelling of 165261389 in words is "one hundred sixty-five million, two hundred sixty-one thousand, three hundred eighty-nine".