43138364221 has 2 divisors, whose sum is σ = 43138364222. Its totient is φ = 43138364220.

The previous prime is 43138364189. The next prime is 43138364233. The reversal of 43138364221 is 12246383134.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31369368996 + 11768995225 = 177114^2 + 108485^2 .

It is a cyclic number.

It is not a de Polignac number, because 43138364221 - 2⁵ = 43138364189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43138364021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21569182110 + 21569182111.

It is an arithmetic number, because the mean of its divisors is an integer number (21569182111).

Almost surely, 2^43138364221 is an apocalyptic number.

It is an amenable number.

43138364221 is a deficient number, since it is larger than the sum of its proper divisors (1).

43138364221 is an equidigital number, since it uses as much as digits as its factorization.

43138364221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 37.

The spelling of 43138364221 in words is "forty-three billion, one hundred thirty-eight million, three hundred sixty-four thousand, two hundred twenty-one".