138776993 has 2 divisors, whose sum is σ = 138776994. Its totient is φ = 138776992.

The previous prime is 138776941. The next prime is 138776999. The reversal of 138776993 is 399677831.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138109504 + 667489 = 11752^2 + 817^2 .

It is a cyclic number.

It is not a de Polignac number, because 138776993 - 2¹⁰ = 138775969 is a prime.

It is a super-2 number, since 2×138776993² = 38518107572244098, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (138776999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69388496 + 69388497.

It is an arithmetic number, because the mean of its divisors is an integer number (69388497).

Almost surely, 2^138776993 is an apocalyptic number.

It is an amenable number.

138776993 is a deficient number, since it is larger than the sum of its proper divisors (1).

138776993 is an equidigital number, since it uses as much as digits as its factorization.

138776993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1714608, while the sum is 53.

The square root of 138776993 is about 11780.3647227070. The cubic root of 138776993 is about 517.7329723431.

The spelling of 138776993 in words is "one hundred thirty-eight million, seven hundred seventy-six thousand, nine hundred ninety-three".