138632881 has 2 divisors, whose sum is σ = 138632882. Its totient is φ = 138632880.

The previous prime is 138632861. The next prime is 138632887. The reversal of 138632881 is 188236831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 136515856 + 2117025 = 11684^2 + 1455^2 .

It is a cyclic number.

It is not a de Polignac number, because 138632881 - 2²³ = 130244273 is a prime.

It is a super-2 number, since 2×138632881² = 38438151388720322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (138632887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69316440 + 69316441.

It is an arithmetic number, because the mean of its divisors is an integer number (69316441).

Almost surely, 2^138632881 is an apocalyptic number.

It is an amenable number.

138632881 is a deficient number, since it is larger than the sum of its proper divisors (1).

138632881 is an equidigital number, since it uses as much as digits as its factorization.

138632881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 55296, while the sum is 40.

The square root of 138632881 is about 11774.2465151703. The cubic root of 138632881 is about 517.5536982093.

The spelling of 138632881 in words is "one hundred thirty-eight million, six hundred thirty-two thousand, eight hundred eighty-one".