138817971 has 54 divisors (see below), whose sum is σ = 228524660. Its totient is φ = 80960256.

The previous prime is 138817963. The next prime is 138817997. The reversal of 138817971 is 179718831.

It is a happy number.

It is not a de Polignac number, because 138817971 - 2³ = 138817963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138817951) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 2619181 + ... + 2619233.

Almost surely, 2^138817971 is an apocalyptic number.

138817971 is a deficient number, since it is larger than the sum of its proper divisors (89706689).

138817971 is a wasteful number, since it uses less digits than its factorization.

138817971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165 (or 92 counting only the distinct ones).

The product of its digits is 84672, while the sum is 45.

The square root of 138817971 is about 11782.1038443904. The cubic root of 138817971 is about 517.7839259713.

The spelling of 138817971 in words is "one hundred thirty-eight million, eight hundred seventeen thousand, nine hundred seventy-one".