2173901861 has 2 divisors, whose sum is σ = 2173901862. Its totient is φ = 2173901860.

The previous prime is 2173901831. The next prime is 2173901867. The reversal of 2173901861 is 1681093712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2173890625 + 11236 = 46625^2 + 106^2 .

It is a cyclic number.

It is not a de Polignac number, because 2173901861 - 2¹⁰ = 2173900837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2173901867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1086950930 + 1086950931.

It is an arithmetic number, because the mean of its divisors is an integer number (1086950931).

Almost surely, 2^2173901861 is an apocalyptic number.

It is an amenable number.

2173901861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2173901861 is an equidigital number, since it uses as much as digits as its factorization.

2173901861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 2173901861 is about 46625.1204931419. The cubic root of 2173901861 is about 1295.4280941823.

The spelling of 2173901861 in words is "two billion, one hundred seventy-three million, nine hundred one thousand, eight hundred sixty-one".