6638445555 has 32 divisors (see below), whose sum is σ = 12530454528. Its totient is φ = 2936822400.

The previous prime is 6638445553. The next prime is 6638445589. The reversal of 6638445555 is 5555448366.

It is not a de Polignac number, because 6638445555 - 2¹ = 6638445553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6638445498 and 6638445507.

It is not an unprimeable number, because it can be changed into a prime (6638445553) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1016476 + ... + 1022985.

It is an arithmetic number, because the mean of its divisors is an integer number (391576704).

Almost surely, 2^6638445555 is an apocalyptic number.

6638445555 is a deficient number, since it is larger than the sum of its proper divisors (5892008973).

6638445555 is a wasteful number, since it uses less digits than its factorization.

6638445555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2039507.

The product of its digits is 8640000, while the sum is 51.

The square root of 6638445555 is about 81476.6565035655. The cubic root of 6638445555 is about 1879.4125932869.

The spelling of 6638445555 in words is "six billion, six hundred thirty-eight million, four hundred forty-five thousand, five hundred fifty-five".