1809640638208 has 36 divisors (see below), whose sum is σ = 3890074864648. Its totient is φ = 835218754560.

The previous prime is 1809640638173. The next prime is 1809640638209. The reversal of 1809640638208 is 8028360469081.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1809640638209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 271877778 + ... + 271884433.

Almost surely, 2^{1809640638208} is an apocalyptic number.

It is an amenable number.

1809640638208 is an abundant number, since it is smaller than the sum of its proper divisors (2080434226440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1809640638208 is an equidigital number, since it uses as much as digits as its factorization.

1809640638208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543762240 (or 543762226 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 55.

The spelling of 1809640638208 in words is "one trillion, eight hundred nine billion, six hundred forty million, six hundred thirty-eight thousand, two hundred eight".