138513731 has 2 divisors, whose sum is σ = 138513732. Its totient is φ = 138513730.

The previous prime is 138513709. The next prime is 138513733. The reversal of 138513731 is 137315831.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138513731 is a prime.

It is a super-2 number, since 2×138513731² = 38372107351080722, which contains 22 as substring.

Together with 138513733, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138513733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69256865 + 69256866.

It is an arithmetic number, because the mean of its divisors is an integer number (69256866).

Almost surely, 2^138513731 is an apocalyptic number.

138513731 is a deficient number, since it is larger than the sum of its proper divisors (1).

138513731 is an equidigital number, since it uses as much as digits as its factorization.

138513731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 32.

The square root of 138513731 is about 11769.1856557708. The cubic root of 138513731 is about 517.4053827499.

The spelling of 138513731 in words is "one hundred thirty-eight million, five hundred thirteen thousand, seven hundred thirty-one".