2161828787 has 4 divisors (see below), whose sum is σ = 2182817520. Its totient is φ = 2140840056.

The previous prime is 2161828777. The next prime is 2161828813. The reversal of 2161828787 is 7878281612.

2161828787 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 2161828787 - 2¹⁶ = 2161763251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2161828717) 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, 10494212 + ... + 10494417.

It is an arithmetic number, because the mean of its divisors is an integer number (545704380).

Almost surely, 2^2161828787 is an apocalyptic number.

2161828787 is a deficient number, since it is larger than the sum of its proper divisors (20988733).

2161828787 is a wasteful number, since it uses less digits than its factorization.

2161828787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20988732.

The product of its digits is 602112, while the sum is 50.

The square root of 2161828787 is about 46495.4706073613. The cubic root of 2161828787 is about 1293.0255261236.

It can be divided in two parts, 21618 and 28787, that added together give a palindrome (50405).

The spelling of 2161828787 in words is "two billion, one hundred sixty-one million, eight hundred twenty-eight thousand, seven hundred eighty-seven".