43205765261 has 2 divisors, whose sum is σ = 43205765262. Its totient is φ = 43205765260.

The previous prime is 43205765237. The next prime is 43205765297. The reversal of 43205765261 is 16256750234.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41725824361 + 1479940900 = 204269^2 + 38470^2 .

It is a cyclic number.

It is not a de Polignac number, because 43205765261 - 2²⁶ = 43138656397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43205765221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21602882630 + 21602882631.

It is an arithmetic number, because the mean of its divisors is an integer number (21602882631).

Almost surely, 2^43205765261 is an apocalyptic number.

It is an amenable number.

43205765261 is a deficient number, since it is larger than the sum of its proper divisors (1).

43205765261 is an equidigital number, since it uses as much as digits as its factorization.

43205765261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 302400, while the sum is 41.

The spelling of 43205765261 in words is "forty-three billion, two hundred five million, seven hundred sixty-five thousand, two hundred sixty-one".