138007391 has 4 divisors (see below), whose sum is σ = 139754400. Its totient is φ = 136260384.

The previous prime is 138007379. The next prime is 138007403. The reversal of 138007391 is 193700831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 193700831 = 29 ⋅6679339.

It is an interprime number because it is at equal distance from previous prime (138007379) and next prime (138007403).

It is a cyclic number.

It is not a de Polignac number, because 138007391 - 2⁶ = 138007327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138007301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 873386 + ... + 873543.

It is an arithmetic number, because the mean of its divisors is an integer number (34938600).

Almost surely, 2^138007391 is an apocalyptic number.

138007391 is a deficient number, since it is larger than the sum of its proper divisors (1747009).

138007391 is an equidigital number, since it uses as much as digits as its factorization.

138007391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1747008.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 138007391 is about 11747.6547021097. The cubic root of 138007391 is about 516.7741506986.

The spelling of 138007391 in words is "one hundred thirty-eight million, seven thousand, three hundred ninety-one".