138611969 has 2 divisors, whose sum is σ = 138611970. Its totient is φ = 138611968.

The previous prime is 138611959. The next prime is 138611983. The reversal of 138611969 is 969116831.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 94322944 + 44289025 = 9712^2 + 6655^2 .

It is a cyclic number.

It is not a de Polignac number, because 138611969 - 2¹² = 138607873 is a prime.

It is a super-2 number, since 2×138611969² = 38426555900113922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (138611929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69305984 + 69305985.

It is an arithmetic number, because the mean of its divisors is an integer number (69305985).

Almost surely, 2^138611969 is an apocalyptic number.

It is an amenable number.

138611969 is a deficient number, since it is larger than the sum of its proper divisors (1).

138611969 is an equidigital number, since it uses as much as digits as its factorization.

138611969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 44.

The square root of 138611969 is about 11773.3584418381. The cubic root of 138611969 is about 517.5276735339.

The spelling of 138611969 in words is "one hundred thirty-eight million, six hundred eleven thousand, nine hundred sixty-nine".