138530931 has 16 divisors (see below), whose sum is σ = 230285568. Its totient is φ = 71964000.

The previous prime is 138530921. The next prime is 138530933. The reversal of 138530931 is 139035831.

It is not a de Polignac number, because 138530931 - 2⁷ = 138530803 is a prime.

It is a super-2 number, since 2×138530931² = 38381637687453522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 138530892 and 138530901.

It is not an unprimeable number, because it can be changed into a prime (138530933) 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 15 ways as a sum of consecutive naturals, for example, 299620 + ... + 300081.

It is an arithmetic number, because the mean of its divisors is an integer number (14392848).

Almost surely, 2^138530931 is an apocalyptic number.

138530931 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

138530931 is a deficient number, since it is larger than the sum of its proper divisors (91754637).

138530931 is a wasteful number, since it uses less digits than its factorization.

138530931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 599722.

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 138530931 is about 11769.9163548430. The cubic root of 138530931 is about 517.4267982062.

The spelling of 138530931 in words is "one hundred thirty-eight million, five hundred thirty thousand, nine hundred thirty-one".