138420977 has 2 divisors, whose sum is σ = 138420978. Its totient is φ = 138420976.

The previous prime is 138420929. The next prime is 138421013. The reversal of 138420977 is 779024831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138321121 + 99856 = 11761^2 + 316^2 .

It is a cyclic number.

It is not a de Polignac number, because 138420977 - 2¹⁸ = 138158833 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138480977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69210488 + 69210489.

It is an arithmetic number, because the mean of its divisors is an integer number (69210489).

Almost surely, 2^138420977 is an apocalyptic number.

It is an amenable number.

138420977 is a deficient number, since it is larger than the sum of its proper divisors (1).

138420977 is an equidigital number, since it uses as much as digits as its factorization.

138420977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84672, while the sum is 41.

The square root of 138420977 is about 11765.2444513491. The cubic root of 138420977 is about 517.2898655979.

The spelling of 138420977 in words is "one hundred thirty-eight million, four hundred twenty thousand, nine hundred seventy-seven".