4138621381 has 4 divisors (see below), whose sum is σ = 4141394892. Its totient is φ = 4135847872.

The previous prime is 4138621379. The next prime is 4138621393. The reversal of 4138621381 is 1831268314.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1849860100 + 2288761281 = 43010^2 + 47841^2 .

It is a cyclic number.

It is not a de Polignac number, because 4138621381 - 2¹ = 4138621379 is a prime.

It is a super-2 number, since 2×4138621381² = 34256373870540694322, 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 4138621381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4138721381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1384516 + ... + 1387501.

It is an arithmetic number, because the mean of its divisors is an integer number (1035348723).

Almost surely, 2^4138621381 is an apocalyptic number.

It is an amenable number.

4138621381 is a deficient number, since it is larger than the sum of its proper divisors (2773511).

4138621381 is a wasteful number, since it uses less digits than its factorization.

4138621381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2773510.

The product of its digits is 27648, while the sum is 37.

The square root of 4138621381 is about 64332.1178028518. The cubic root of 4138621381 is about 1605.5305202991.

Adding to 4138621381 its reverse (1831268314), we get a palindrome (5969889695).

The spelling of 4138621381 in words is "four billion, one hundred thirty-eight million, six hundred twenty-one thousand, three hundred eighty-one".