6446406509 has 2 divisors, whose sum is σ = 6446406510. Its totient is φ = 6446406508.

The previous prime is 6446406479. The next prime is 6446406521. The reversal of 6446406509 is 9056046446.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5894861284 + 551545225 = 76778^2 + 23485^2 .

It is a cyclic number.

It is not a de Polignac number, because 6446406509 - 2²⁴ = 6429629293 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6446406509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6446406529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3223203254 + 3223203255.

It is an arithmetic number, because the mean of its divisors is an integer number (3223203255).

Almost surely, 2^6446406509 is an apocalyptic number.

It is an amenable number.

6446406509 is a deficient number, since it is larger than the sum of its proper divisors (1).

6446406509 is an equidigital number, since it uses as much as digits as its factorization.

6446406509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 44.

The square root of 6446406509 is about 80289.5168063677. The cubic root of 6446406509 is about 1861.1122292426.

The spelling of 6446406509 in words is "six billion, four hundred forty-six million, four hundred six thousand, five hundred nine".