138852781 has 2 divisors, whose sum is σ = 138852782. Its totient is φ = 138852780.

The previous prime is 138852767. The next prime is 138852793. The reversal of 138852781 is 187258831.

138852781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90897156 + 47955625 = 9534^2 + 6925^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138852781 is a prime.

It is a super-2 number, since 2×138852781² = 38560189582867922, which contains 22 as substring.

It is a pancake number, because a pancake can be divided into 138852781 parts by 16664 straight cuts.

It is equal to p_7850896 and since 138852781 and 7850896 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138832781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69426390 + 69426391.

It is an arithmetic number, because the mean of its divisors is an integer number (69426391).

Almost surely, 2^138852781 is an apocalyptic number.

It is an amenable number.

138852781 is a deficient number, since it is larger than the sum of its proper divisors (1).

138852781 is an equidigital number, since it uses as much as digits as its factorization.

138852781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 107520, while the sum is 43.

The square root of 138852781 is about 11783.5809922112. The cubic root of 138852781 is about 517.8272021935.

The spelling of 138852781 in words is "one hundred thirty-eight million, eight hundred fifty-two thousand, seven hundred eighty-one".