138917930 has 64 divisors (see below), whose sum is σ = 278691840. Its totient is φ = 49617216.

The previous prime is 138917927. The next prime is 138917957. The reversal of 138917930 is 39719831.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 362519 + ... + 362901.

It is an arithmetic number, because the mean of its divisors is an integer number (4354560).

Almost surely, 2^138917930 is an apocalyptic number.

138917930 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138917930 is an abundant number, since it is smaller than the sum of its proper divisors (139773910).

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

138917930 is a wasteful number, since it uses less digits than its factorization.

138917930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515.

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 138917930 is about 11786.3450653712. The cubic root of 138917930 is about 517.9081768039.

The spelling of 138917930 in words is "one hundred thirty-eight million, nine hundred seventeen thousand, nine hundred thirty".