6445623328 has 12 divisors (see below), whose sum is σ = 12689820990. Its totient is φ = 3222811648.

The previous prime is 6445623313. The next prime is 6445623341. The reversal of 6445623328 is 8233265446.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 6113363344 + 332259984 = 78188^2 + 18228^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100712833 + ... + 100712896.

Almost surely, 2^6445623328 is an apocalyptic number.

It is an amenable number.

6445623328 is a deficient number, since it is larger than the sum of its proper divisors (6244197662).

6445623328 is a wasteful number, since it uses less digits than its factorization.

6445623328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201425739 (or 201425731 counting only the distinct ones).

The product of its digits is 829440, while the sum is 43.

The square root of 6445623328 is about 80284.6394274770. The cubic root of 6445623328 is about 1861.0368566679.

The spelling of 6445623328 in words is "six billion, four hundred forty-five million, six hundred twenty-three thousand, three hundred twenty-eight".