138181447 has 16 divisors (see below), whose sum is σ = 146849472. Its totient is φ = 129761280.

The previous prime is 138181397. The next prime is 138181487. The reversal of 138181447 is 744181831.

It is a cyclic number.

It is not a de Polignac number, because 138181447 - 2¹¹ = 138179399 is a prime.

It is a super-2 number, since 2×138181447² = 38188224590027618, 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 (138181487) 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, 537543 + ... + 537799.

It is an arithmetic number, because the mean of its divisors is an integer number (9178092).

Almost surely, 2^138181447 is an apocalyptic number.

138181447 is a deficient number, since it is larger than the sum of its proper divisors (8668025).

138181447 is a wasteful number, since it uses less digits than its factorization.

138181447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 618.

The product of its digits is 21504, while the sum is 37.

The square root of 138181447 is about 11755.0604847444. The cubic root of 138181447 is about 516.9913126278.

It can be divided in two parts, 1381 and 81447, that added together give a palindrome (82828).

The spelling of 138181447 in words is "one hundred thirty-eight million, one hundred eighty-one thousand, four hundred forty-seven".