138858890 has 16 divisors (see below), whose sum is σ = 264649032. Its totient is φ = 52276224.

The previous prime is 138858877. The next prime is 138858893. The reversal of 138858890 is 98858831.

It can be written as a sum of positive squares in 4 ways, for example, as 126405049 + 12453841 = 11243^2 + 3529^2 .

It is not an unprimeable number, because it can be changed into a prime (138858893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 408239 + ... + 408578.

Almost surely, 2^138858890 is an apocalyptic number.

138858890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138858890 is a deficient number, since it is larger than the sum of its proper divisors (125790142).

138858890 is a wasteful number, since it uses less digits than its factorization.

138858890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 816841.

The product of its (nonzero) digits is 552960, while the sum is 50.

The square root of 138858890 is about 11783.8402059770. The cubic root of 138858890 is about 517.8347962318.

The spelling of 138858890 in words is "one hundred thirty-eight million, eight hundred fifty-eight thousand, eight hundred ninety".