138209139 has 32 divisors (see below), whose sum is σ = 214563840. Its totient is φ = 87759936.

The previous prime is 138209131. The next prime is 138209153. The reversal of 138209139 is 931902831.

It is not a de Polignac number, because 138209139 - 2³ = 138209131 is a prime.

It is a super-2 number, since 2×138209139² = 38203532206242642, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138209131) 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, 283554 + ... + 284040.

It is an arithmetic number, because the mean of its divisors is an integer number (6705120).

Almost surely, 2^138209139 is an apocalyptic number.

138209139 is a deficient number, since it is larger than the sum of its proper divisors (76354701).

138209139 is a wasteful number, since it uses less digits than its factorization.

138209139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 976 (or 970 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 138209139 is about 11756.2383014296. The cubic root of 138209139 is about 517.0258458870.

The spelling of 138209139 in words is "one hundred thirty-eight million, two hundred nine thousand, one hundred thirty-nine".