138871949 has 2 divisors, whose sum is σ = 138871950. Its totient is φ = 138871948.

The previous prime is 138871937. The next prime is 138871973. The reversal of 138871949 is 949178831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 119202724 + 19669225 = 10918^2 + 4435^2 .

It is a cyclic number.

It is not a de Polignac number, because 138871949 - 2⁴ = 138871933 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 138871897 and 138871906.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138871919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69435974 + 69435975.

It is an arithmetic number, because the mean of its divisors is an integer number (69435975).

Almost surely, 2^138871949 is an apocalyptic number.

It is an amenable number.

138871949 is a deficient number, since it is larger than the sum of its proper divisors (1).

138871949 is an equidigital number, since it uses as much as digits as its factorization.

138871949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 50.

The square root of 138871949 is about 11784.3942992417. The cubic root of 138871949 is about 517.8510290002.

It can be divided in two parts, 1388 and 71949, that added together give a palindrome (73337).

The spelling of 138871949 in words is "one hundred thirty-eight million, eight hundred seventy-one thousand, nine hundred forty-nine".