43839421 has 2 divisors, whose sum is σ = 43839422. Its totient is φ = 43839420.

The previous prime is 43839407. The next prime is 43839431. The reversal of 43839421 is 12493834.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31236921 + 12602500 = 5589^2 + 3550^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43839421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43839431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21919710 + 21919711.

It is an arithmetic number, because the mean of its divisors is an integer number (21919711).

Almost surely, 2^43839421 is an apocalyptic number.

It is an amenable number.

43839421 is a deficient number, since it is larger than the sum of its proper divisors (1).

43839421 is an equidigital number, since it uses as much as digits as its factorization.

43839421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 34.

The square root of 43839421 is about 6621.1344194179. The cubic root of 43839421 is about 352.6048404683.

The spelling of 43839421 in words is "forty-three million, eight hundred thirty-nine thousand, four hundred twenty-one".