138694477 has 2 divisors, whose sum is σ = 138694478. Its totient is φ = 138694476.

The previous prime is 138694441. The next prime is 138694499. The reversal of 138694477 is 774496831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74149321 + 64545156 = 8611^2 + 8034^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138694477 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138694477.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138694877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69347238 + 69347239.

It is an arithmetic number, because the mean of its divisors is an integer number (69347239).

Almost surely, 2^138694477 is an apocalyptic number.

It is an amenable number.

138694477 is a deficient number, since it is larger than the sum of its proper divisors (1).

138694477 is an equidigital number, since it uses as much as digits as its factorization.

138694477 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 49.

The square root of 138694477 is about 11776.8619334694. The cubic root of 138694477 is about 517.6303383183.

The spelling of 138694477 in words is "one hundred thirty-eight million, six hundred ninety-four thousand, four hundred seventy-seven".