2001855021887 has 4 divisors (see below), whose sum is σ = 2287834310736. Its totient is φ = 1715875733040.

The previous prime is 2001855021811. The next prime is 2001855021923. The reversal of 2001855021887 is 7881205581002.

It is a happy number.

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

It is not a de Polignac number, because 2001855021887 - 2¹⁴ = 2001855005503 is a prime.

It is a super-3 number, since 3×2001855021887³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001855011887) 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, 142989644414 + ... + 142989644427.

It is an arithmetic number, because the mean of its divisors is an integer number (571958577684).

Almost surely, 2^{2001855021887} is an apocalyptic number.

2001855021887 is a deficient number, since it is larger than the sum of its proper divisors (285979288849).

2001855021887 is an equidigital number, since it uses as much as digits as its factorization.

2001855021887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285979288848.

The product of its (nonzero) digits is 358400, while the sum is 47.

The spelling of 2001855021887 in words is "two trillion, one billion, eight hundred fifty-five million, twenty-one thousand, eight hundred eighty-seven".