1638809608403 has 4 divisors (see below), whose sum is σ = 1787792300088. Its totient is φ = 1489826916720.

The previous prime is 1638809608399. The next prime is 1638809608411. The reversal of 1638809608403 is 3048069088361.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1638809608403 - 2² = 1638809608399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1638809608493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74491345826 + ... + 74491345847.

It is an arithmetic number, because the mean of its divisors is an integer number (446948075022).

Almost surely, 2^{1638809608403} is an apocalyptic number.

1638809608403 is a deficient number, since it is larger than the sum of its proper divisors (148982691685).

1638809608403 is a wasteful number, since it uses less digits than its factorization.

1638809608403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148982691684.

The product of its (nonzero) digits is 5971968, while the sum is 56.

The spelling of 1638809608403 in words is "one trillion, six hundred thirty-eight billion, eight hundred nine million, six hundred eight thousand, four hundred three".