138263581 has 8 divisors (see below), whose sum is σ = 139908384. Its totient is φ = 136625520.

The previous prime is 138263569. The next prime is 138263599. The reversal of 138263581 is 185362831.

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

It is a cyclic number.

It is not a de Polignac number, because 138263581 - 2⁷ = 138263453 is a prime.

It is a super-2 number, since 2×138263581² = 38233635661887122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138263581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138263981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47926 + ... + 50728.

It is an arithmetic number, because the mean of its divisors is an integer number (17488548).

Almost surely, 2^138263581 is an apocalyptic number.

It is an amenable number.

138263581 is a deficient number, since it is larger than the sum of its proper divisors (1644803).

138263581 is a wasteful number, since it uses less digits than its factorization.

138263581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3371.

The product of its digits is 34560, while the sum is 37.

The square root of 138263581 is about 11758.5535249877. The cubic root of 138263581 is about 517.0937242396.

The spelling of 138263581 in words is "one hundred thirty-eight million, two hundred sixty-three thousand, five hundred eighty-one".