138648890 has 32 divisors (see below), whose sum is σ = 265446720. Its totient is φ = 51992064.

The previous prime is 138648883. The next prime is 138648893. The reversal of 138648890 is 98846831.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (138648893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14669 + ... + 22191.

It is an arithmetic number, because the mean of its divisors is an integer number (8295210).

Almost surely, 2^138648890 is an apocalyptic number.

138648890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138648890 is a deficient number, since it is larger than the sum of its proper divisors (126797830).

138648890 is a wasteful number, since it uses less digits than its factorization.

138648890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7646.

The product of its (nonzero) digits is 331776, while the sum is 47.

The square root of 138648890 is about 11774.9263267334. The cubic root of 138648890 is about 517.5736194050.

The spelling of 138648890 in words is "one hundred thirty-eight million, six hundred forty-eight thousand, eight hundred ninety".