2171577851 has 4 divisors (see below), whose sum is σ = 2212551072. Its totient is φ = 2130604632.

The previous prime is 2171577847. The next prime is 2171577853. The reversal of 2171577851 is 1587751712.

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 2171577851 - 2² = 2171577847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2171577853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20486531 + ... + 20486636.

It is an arithmetic number, because the mean of its divisors is an integer number (553137768).

Almost surely, 2^2171577851 is an apocalyptic number.

2171577851 is a deficient number, since it is larger than the sum of its proper divisors (40973221).

2171577851 is an equidigital number, since it uses as much as digits as its factorization.

2171577851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40973220.

The product of its digits is 137200, while the sum is 44.

The square root of 2171577851 is about 46600.1915339411. The cubic root of 2171577851 is about 1294.9663037400.

The spelling of 2171577851 in words is "two billion, one hundred seventy-one million, five hundred seventy-seven thousand, eight hundred fifty-one".