6446478385 has 8 divisors (see below), whose sum is σ = 7736841000. Its totient is φ = 5156471424.

The previous prime is 6446478377. The next prime is 6446478461. The reversal of 6446478385 is 5838746446.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1211666481 + 5234811904 = 34809^2 + 72352^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6446478385 - 2³ = 6446478377 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47260 + ... + 122989.

It is an arithmetic number, because the mean of its divisors is an integer number (967105125).

Almost surely, 2^6446478385 is an apocalyptic number.

It is an amenable number.

6446478385 is a deficient number, since it is larger than the sum of its proper divisors (1290362615).

6446478385 is a wasteful number, since it uses less digits than its factorization.

6446478385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177827.

The product of its digits is 15482880, while the sum is 55.

The square root of 6446478385 is about 80289.9644102549. The cubic root of 6446478385 is about 1861.1191462128.

The spelling of 6446478385 in words is "six billion, four hundred forty-six million, four hundred seventy-eight thousand, three hundred eighty-five".