2171774921 has 2 divisors, whose sum is σ = 2171774922. Its totient is φ = 2171774920.

The previous prime is 2171774863. The next prime is 2171774947. The reversal of 2171774921 is 1294771712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1705690000 + 466084921 = 41300^2 + 21589^2 .

It is a cyclic number.

It is not a de Polignac number, because 2171774921 - 2¹⁰ = 2171773897 is a prime.

It is not a weakly prime, because it can be changed into another prime (2171774971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1085887460 + 1085887461.

It is an arithmetic number, because the mean of its divisors is an integer number (1085887461).

Almost surely, 2^2171774921 is an apocalyptic number.

It is an amenable number.

2171774921 is a deficient number, since it is larger than the sum of its proper divisors (1).

2171774921 is an equidigital number, since it uses as much as digits as its factorization.

2171774921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 49392, while the sum is 41.

The square root of 2171774921 is about 46602.3059622590. The cubic root of 2171774921 is about 1295.0054751487.

The spelling of 2171774921 in words is "two billion, one hundred seventy-one million, seven hundred seventy-four thousand, nine hundred twenty-one".