138021385 has 8 divisors (see below), whose sum is σ = 175368456. Its totient is φ = 103921920.

The previous prime is 138021361. The next prime is 138021431. The reversal of 138021385 is 583120831.

It can be written as a sum of positive squares in 4 ways, for example, as 63872064 + 74149321 = 7992^2 + 8611^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138021385 - 2¹¹ = 138019337 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 811806 + ... + 811975.

It is an arithmetic number, because the mean of its divisors is an integer number (21921057).

Almost surely, 2^138021385 is an apocalyptic number.

It is an amenable number.

138021385 is a deficient number, since it is larger than the sum of its proper divisors (37347071).

138021385 is a wasteful number, since it uses less digits than its factorization.

138021385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1623803.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 138021385 is about 11748.2502952567. The cubic root of 138021385 is about 516.7916171377.

The spelling of 138021385 in words is "one hundred thirty-eight million, twenty-one thousand, three hundred eighty-five".