138481793 has 2 divisors, whose sum is σ = 138481794. Its totient is φ = 138481792.

The previous prime is 138481789. The next prime is 138481799. The reversal of 138481793 is 397184831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130347889 + 8133904 = 11417^2 + 2852^2 .

It is an emirp because it is prime and its reverse (397184831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138481793 - 2² = 138481789 is a prime.

It is not a weakly prime, because it can be changed into another prime (138481799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69240896 + 69240897.

It is an arithmetic number, because the mean of its divisors is an integer number (69240897).

Almost surely, 2^138481793 is an apocalyptic number.

It is an amenable number.

138481793 is a deficient number, since it is larger than the sum of its proper divisors (1).

138481793 is an equidigital number, since it uses as much as digits as its factorization.

138481793 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 44.

The square root of 138481793 is about 11767.8287292091. The cubic root of 138481793 is about 517.3656125331.

The spelling of 138481793 in words is "one hundred thirty-eight million, four hundred eighty-one thousand, seven hundred ninety-three".