138217500 has 90 divisors (see below), whose sum is σ = 436660224. Its totient is φ = 36852000.

The previous prime is 138217489. The next prime is 138217577. The reversal of 138217500 is 5712831.

138217500 is a `hidden beast` number, since 138 + 21 + 7 + 500 = 666.

It is a tau number, because it is divible by the number of its divisors (90).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 19429 + ... + 25571.

Almost surely, 2^138217500 is an apocalyptic number.

138217500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138217500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (218330112).

138217500 is an abundant number, since it is smaller than the sum of its proper divisors (298442724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138217500 is a wasteful number, since it uses less digits than its factorization.

138217500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6173 (or 6153 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 138217500 is about 11756.5938944917. The cubic root of 138217500 is about 517.0362715505.

It can be divided in two parts, 13821 and 7500, that added together give a triangular number (21321 = T₂₀₆).

The spelling of 138217500 in words is "one hundred thirty-eight million, two hundred seventeen thousand, five hundred".