138665250 has 64 divisors (see below), whose sum is σ = 384583680. Its totient is φ = 36975600.

The previous prime is 138665227. The next prime is 138665251. The reversal of 138665250 is 52566831.

It is not an unprimeable number, because it can be changed into a prime (138665251) 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, 3522 + ... + 17021.

It is an arithmetic number, because the mean of its divisors is an integer number (6009120).

Almost surely, 2^138665250 is an apocalyptic number.

138665250 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138665250 is an abundant number, since it is smaller than the sum of its proper divisors (245918430).

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

138665250 is a wasteful number, since it uses less digits than its factorization.

138665250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20569 (or 20553 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 138665250 is about 11775.6210027327. The cubic root of 138665250 is about 517.5939757920.

The spelling of 138665250 in words is "one hundred thirty-eight million, six hundred sixty-five thousand, two hundred fifty".