138398381 has 16 divisors (see below), whose sum is σ = 156074688. Its totient is φ = 121632000.

The previous prime is 138398371. The next prime is 138398387. The reversal of 138398381 is 183893831.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138398381 is a prime.

It is a super-2 number, since 2×138398381² = 38308223726842322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138398387) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46325 + ... + 49221.

It is an arithmetic number, because the mean of its divisors is an integer number (9754668).

Almost surely, 2^138398381 is an apocalyptic number.

138398381 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

138398381 is a deficient number, since it is larger than the sum of its proper divisors (17676307).

138398381 is a wasteful number, since it uses less digits than its factorization.

138398381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3052.

The product of its digits is 124416, while the sum is 44.

The square root of 138398381 is about 11764.2841261166. The cubic root of 138398381 is about 517.2617164013.

The spelling of 138398381 in words is "one hundred thirty-eight million, three hundred ninety-eight thousand, three hundred eighty-one".