138809517 has 32 divisors (see below), whose sum is σ = 231828480. Its totient is φ = 71771520.

The previous prime is 138809513. The next prime is 138809521. The reversal of 138809517 is 715908831.

138809517 is nontrivially palindromic in base 15.

It is an interprime number because it is at equal distance from previous prime (138809513) and next prime (138809521).

It is not a de Polignac number, because 138809517 - 2² = 138809513 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138809513) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52534 + ... + 55112.

It is an arithmetic number, because the mean of its divisors is an integer number (7244640).

Almost surely, 2^138809517 is an apocalyptic number.

It is an amenable number.

138809517 is a deficient number, since it is larger than the sum of its proper divisors (93018963).

138809517 is a wasteful number, since it uses less digits than its factorization.

138809517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2833.

The product of its (nonzero) digits is 60480, while the sum is 42.

The square root of 138809517 is about 11781.7450744786. The cubic root of 138809517 is about 517.7734147622.

The spelling of 138809517 in words is "one hundred thirty-eight million, eight hundred nine thousand, five hundred seventeen".