2185781565642 has 16 divisors (see below), whose sum is σ = 4383740191680. Its totient is φ = 726564345152.

The previous prime is 2185781565641. The next prime is 2185781565661. The reversal of 2185781565642 is 2465651875812.

It is a Smith number, since the sum of its digits (60) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (2185781565641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 507375183 + ... + 507379490.

It is an arithmetic number, because the mean of its divisors is an integer number (273983761980).

Almost surely, 2^{2185781565642} is an apocalyptic number.

2185781565642 is an abundant number, since it is smaller than the sum of its proper divisors (2197958626038).

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

2185781565642 is a wasteful number, since it uses less digits than its factorization.

2185781565642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1014755037.

The product of its digits is 32256000, while the sum is 60.

The spelling of 2185781565642 in words is "two trillion, one hundred eighty-five billion, seven hundred eighty-one million, five hundred sixty-five thousand, six hundred forty-two".