43813381 has 4 divisors (see below), whose sum is σ = 43827372. Its totient is φ = 43799392.

The previous prime is 43813361. The next prime is 43813387. The reversal of 43813381 is 18331834.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18331834 = 2 ⋅9165917.

It can be written as a sum of positive squares in 2 ways, for example, as 4950625 + 38862756 = 2225^2 + 6234^2 .

It is a cyclic number.

It is not a de Polignac number, because 43813381 - 2¹¹ = 43811333 is a prime.

It is a super-2 number, since 2×43813381² = 3839224709302322, 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 (43813387) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105 + ... + 9361.

It is an arithmetic number, because the mean of its divisors is an integer number (10956843).

Almost surely, 2^43813381 is an apocalyptic number.

It is an amenable number.

43813381 is a deficient number, since it is larger than the sum of its proper divisors (13991).

43813381 is an equidigital number, since it uses as much as digits as its factorization.

43813381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13990.

The product of its digits is 6912, while the sum is 31.

The square root of 43813381 is about 6619.1676969238. The cubic root of 43813381 is about 352.5350125342.

The spelling of 43813381 in words is "forty-three million, eight hundred thirteen thousand, three hundred eighty-one".