1855216868887 has 4 divisors (see below), whose sum is σ = 1856917343736. Its totient is φ = 1853516394040.

The previous prime is 1855216868863. The next prime is 1855216868929. The reversal of 1855216868887 is 7888686125581.

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 1855216868887 - 2³¹ = 1853069385239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1855216868587) 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, 850235788 + ... + 850237969.

It is an arithmetic number, because the mean of its divisors is an integer number (464229335934).

Almost surely, 2^{1855216868887} is an apocalyptic number.

1855216868887 is a deficient number, since it is larger than the sum of its proper divisors (1700474849).

1855216868887 is a wasteful number, since it uses less digits than its factorization.

1855216868887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1700474848.

The product of its digits is 412876800, while the sum is 73.

The spelling of 1855216868887 in words is "one trillion, eight hundred fifty-five billion, two hundred sixteen million, eight hundred sixty-eight thousand, eight hundred eighty-seven".