138569 has 2 divisors, whose sum is σ = 138570. Its totient is φ = 138568.

The previous prime is 138563. The next prime is 138571. The reversal of 138569 is 965831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 126025 + 12544 = 355^2 + 112^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138569 is a prime.

It is a super-2 number, since 2×138569² = 38402735522, which contains 22 as substring.

Together with 138571, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69284 + 69285.

It is an arithmetic number, because the mean of its divisors is an integer number (69285).

2¹³⁸⁵⁶⁹ is an apocalyptic number.

It is an amenable number.

138569 is a deficient number, since it is larger than the sum of its proper divisors (1).

138569 is an equidigital number, since it uses as much as digits as its factorization.

138569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 32.

The square root of 138569 is about 372.2485728650. The cubic root of 138569 is about 51.7474191032.

Adding to 138569 its sum of digits (32), we get a triangular number (138601 = T₅₂₆).

It can be divided in two parts, 138 and 569, that added together give a palindrome (707).

The spelling of 138569 in words is "one hundred thirty-eight thousand, five hundred sixty-nine".