138985237 has 4 divisors (see below), whose sum is σ = 139083660. Its totient is φ = 138886816.

The previous prime is 138985201. The next prime is 138985289. The reversal of 138985237 is 732589831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 732589831 = 79 ⋅9273289.

It can be written as a sum of positive squares in 2 ways, for example, as 88943761 + 50041476 = 9431^2 + 7074^2 .

It is a cyclic number.

It is not a de Polignac number, because 138985237 - 2⁷ = 138985109 is a prime.

It is a super-2 number, since 2×138985237² = 38633792207892338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138985937) 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 3 ways as a sum of consecutive naturals, for example, 47062 + ... + 49927.

It is an arithmetic number, because the mean of its divisors is an integer number (34770915).

Almost surely, 2^138985237 is an apocalyptic number.

It is an amenable number.

138985237 is a deficient number, since it is larger than the sum of its proper divisors (98423).

138985237 is an equidigital number, since it uses as much as digits as its factorization.

138985237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98422.

The product of its digits is 362880, while the sum is 46.

The square root of 138985237 is about 11789.2000152682. The cubic root of 138985237 is about 517.9918070389.

The spelling of 138985237 in words is "one hundred thirty-eight million, nine hundred eighty-five thousand, two hundred thirty-seven".