43366016521 has 2 divisors, whose sum is σ = 43366016522. Its totient is φ = 43366016520.

The previous prime is 43366016509. The next prime is 43366016539. The reversal of 43366016521 is 12561066334.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37504582921 + 5861433600 = 193661^2 + 76560^2 .

It is a cyclic number.

It is not a de Polignac number, because 43366016521 - 2⁵ = 43366016489 is a prime.

It is a super-2 number, since 2×43366016521² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (43366016501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21683008260 + 21683008261.

It is an arithmetic number, because the mean of its divisors is an integer number (21683008261).

Almost surely, 2^43366016521 is an apocalyptic number.

It is an amenable number.

43366016521 is a deficient number, since it is larger than the sum of its proper divisors (1).

43366016521 is an equidigital number, since it uses as much as digits as its factorization.

43366016521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 37.

The spelling of 43366016521 in words is "forty-three billion, three hundred sixty-six million, sixteen thousand, five hundred twenty-one".