138781901 has 2 divisors, whose sum is σ = 138781902. Its totient is φ = 138781900.

The previous prime is 138781847. The next prime is 138781913. The reversal of 138781901 is 109187831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138532900 + 249001 = 11770^2 + 499^2 .

It is a cyclic number.

It is not a de Polignac number, because 138781901 - 2⁶ = 138781837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138781921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69390950 + 69390951.

It is an arithmetic number, because the mean of its divisors is an integer number (69390951).

Almost surely, 2^138781901 is an apocalyptic number.

It is an amenable number.

138781901 is a deficient number, since it is larger than the sum of its proper divisors (1).

138781901 is an equidigital number, since it uses as much as digits as its factorization.

138781901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 38.

The square root of 138781901 is about 11780.5730336007. The cubic root of 138781901 is about 517.7390756686.

The spelling of 138781901 in words is "one hundred thirty-eight million, seven hundred eighty-one thousand, nine hundred one".