2171621637349 has 2 divisors, whose sum is σ = 2171621637350. Its totient is φ = 2171621637348.

The previous prime is 2171621637313. The next prime is 2171621637391. The reversal of 2171621637349 is 9437361261712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2103921240100 + 67700397249 = 1450490^2 + 260193^2 .

It is a cyclic number.

It is not a de Polignac number, because 2171621637349 - 2¹¹ = 2171621635301 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2171621637296 and 2171621637305.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2171621638349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1085810818674 + 1085810818675.

It is an arithmetic number, because the mean of its divisors is an integer number (1085810818675).

Almost surely, 2^{2171621637349} is an apocalyptic number.

It is an amenable number.

2171621637349 is a deficient number, since it is larger than the sum of its proper divisors (1).

2171621637349 is an equidigital number, since it uses as much as digits as its factorization.

2171621637349 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2286144, while the sum is 52.

The spelling of 2171621637349 in words is "two trillion, one hundred seventy-one billion, six hundred twenty-one million, six hundred thirty-seven thousand, three hundred forty-nine".