138210742 has 4 divisors (see below), whose sum is σ = 207316116. Its totient is φ = 69105370.

The previous prime is 138210739. The next prime is 138210757. The reversal of 138210742 is 247012831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 247012831 = 13 ⋅19000987.

It is a self number, because there is not a number n which added to its sum of digits gives 138210742.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34552684 + ... + 34552687.

It is an arithmetic number, because the mean of its divisors is an integer number (51829029).

Almost surely, 2^138210742 is an apocalyptic number.

138210742 is a deficient number, since it is larger than the sum of its proper divisors (69105374).

138210742 is an equidigital number, since it uses as much as digits as its factorization.

138210742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69105373.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 138210742 is about 11756.3064778016. The cubic root of 138210742 is about 517.0278447641.

The spelling of 138210742 in words is "one hundred thirty-eight million, two hundred ten thousand, seven hundred forty-two".