43444356521 has 2 divisors, whose sum is σ = 43444356522. Its totient is φ = 43444356520.

The previous prime is 43444356509. The next prime is 43444356523. The reversal of 43444356521 is 12565344434.

43444356521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28225680025 + 15218676496 = 168005^2 + 123364^2 .

It is a cyclic number.

It is not a de Polignac number, because 43444356521 - 2²² = 43440162217 is a prime.

It is a super-2 number, since 2×43444356521² (a number of 22 digits) contains 22 as substring.

Together with 43444356523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (43444356523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21722178260 + 21722178261.

It is an arithmetic number, because the mean of its divisors is an integer number (21722178261).

Almost surely, 2^43444356521 is an apocalyptic number.

It is an amenable number.

43444356521 is a deficient number, since it is larger than the sum of its proper divisors (1).

43444356521 is an equidigital number, since it uses as much as digits as its factorization.

43444356521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 691200, while the sum is 41.

The spelling of 43444356521 in words is "forty-three billion, four hundred forty-four million, three hundred fifty-six thousand, five hundred twenty-one".