2171446661 has 4 divisors (see below), whose sum is σ = 2191368300. Its totient is φ = 2151525024.

The previous prime is 2171446609. The next prime is 2171446663. The reversal of 2171446661 is 1666441712.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1943134561 + 228312100 = 44081^2 + 15110^2 .

It is a cyclic number.

It is not a de Polignac number, because 2171446661 - 2¹⁸ = 2171184517 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 (2171446663) 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, 9960656 + ... + 9960873.

It is an arithmetic number, because the mean of its divisors is an integer number (547842075).

Almost surely, 2^2171446661 is an apocalyptic number.

It is an amenable number.

2171446661 is a deficient number, since it is larger than the sum of its proper divisors (19921639).

2171446661 is a wasteful number, since it uses less digits than its factorization.

2171446661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19921638.

The product of its digits is 48384, while the sum is 38.

The square root of 2171446661 is about 46598.7839004410. The cubic root of 2171446661 is about 1294.9402259198.

The spelling of 2171446661 in words is "two billion, one hundred seventy-one million, four hundred forty-six thousand, six hundred sixty-one".