138891847 has 2 divisors, whose sum is σ = 138891848. Its totient is φ = 138891846.

The previous prime is 138891829. The next prime is 138891859. The reversal of 138891847 is 748198831.

It is a strong prime.

It is an emirp because it is prime and its reverse (748198831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138891847 - 2¹¹ = 138889799 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138891847.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138891647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69445923 + 69445924.

It is an arithmetic number, because the mean of its divisors is an integer number (69445924).

Almost surely, 2^138891847 is an apocalyptic number.

138891847 is a deficient number, since it is larger than the sum of its proper divisors (1).

138891847 is an equidigital number, since it uses as much as digits as its factorization.

138891847 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 49.

The square root of 138891847 is about 11785.2385211331. The cubic root of 138891847 is about 517.8757609151.

The spelling of 138891847 in words is "one hundred thirty-eight million, eight hundred ninety-one thousand, eight hundred forty-seven".