43838521 has 2 divisors, whose sum is σ = 43838522. Its totient is φ = 43838520.

The previous prime is 43838519. The next prime is 43838537. The reversal of 43838521 is 12583834.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27678121 + 16160400 = 5261^2 + 4020^2 .

It is a cyclic number.

It is not a de Polignac number, because 43838521 - 2¹ = 43838519 is a prime.

Together with 43838519, it forms a pair of twin primes.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (43838591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21919260 + 21919261.

It is an arithmetic number, because the mean of its divisors is an integer number (21919261).

Almost surely, 2^43838521 is an apocalyptic number.

It is an amenable number.

43838521 is a deficient number, since it is larger than the sum of its proper divisors (1).

43838521 is an equidigital number, since it uses as much as digits as its factorization.

43838521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 34.

The square root of 43838521 is about 6621.0664548847. The cubic root of 43838521 is about 352.6024275218.

The spelling of 43838521 in words is "forty-three million, eight hundred thirty-eight thousand, five hundred twenty-one".