138442237 has 16 divisors (see below), whose sum is σ = 149498352. Its totient is φ = 127733760.

The previous prime is 138442231. The next prime is 138442253. The reversal of 138442237 is 732244831.

138442237 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 17023876 + 121418361 = 4126^2 + 11019^2 .

It is a cyclic number.

It is not a de Polignac number, because 138442237 - 2¹¹ = 138440189 is a prime.

It is a Duffinian number.

Its product of digits (32256) is a multiple of the sum of its prime divisors (768).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138442231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 348523 + ... + 348919.

It is an arithmetic number, because the mean of its divisors is an integer number (9343647).

Almost surely, 2^138442237 is an apocalyptic number.

138442237 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

138442237 is a deficient number, since it is larger than the sum of its proper divisors (11056115).

138442237 is a wasteful number, since it uses less digits than its factorization.

138442237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 768.

The product of its digits is 32256, while the sum is 34.

The square root of 138442237 is about 11766.1479252982. The cubic root of 138442237 is about 517.3163476620.

The spelling of 138442237 in words is "one hundred thirty-eight million, four hundred forty-two thousand, two hundred thirty-seven".