138777512749 has 2 divisors, whose sum is σ = 138777512750. Its totient is φ = 138777512748.

The previous prime is 138777512743. The next prime is 138777512771. The reversal of 138777512749 is 947215777831.

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., 127650427524 + 11127085225 = 357282^2 + 105485^2 .

It is a cyclic number.

It is not a de Polignac number, because 138777512749 - 2²³ = 138769124141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138777512743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69388756374 + 69388756375.

It is an arithmetic number, because the mean of its divisors is an integer number (69388756375).

Almost surely, 2^138777512749 is an apocalyptic number.

It is an amenable number.

138777512749 is a deficient number, since it is larger than the sum of its proper divisors (1).

138777512749 is an equidigital number, since it uses as much as digits as its factorization.

138777512749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20744640, while the sum is 61.

The spelling of 138777512749 in words is "one hundred thirty-eight billion, seven hundred seventy-seven million, five hundred twelve thousand, seven hundred forty-nine".