2178649291901 has 2 divisors, whose sum is σ = 2178649291902. Its totient is φ = 2178649291900.

The previous prime is 2178649291837. The next prime is 2178649291961. The reversal of 2178649291901 is 1091929468712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1606553715001 + 572095576900 = 1267499^2 + 756370^2 .

It is a cyclic number.

It is not a de Polignac number, because 2178649291901 - 2⁶ = 2178649291837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2178649291961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1089324645950 + 1089324645951.

It is an arithmetic number, because the mean of its divisors is an integer number (1089324645951).

Almost surely, 2^{2178649291901} is an apocalyptic number.

It is an amenable number.

2178649291901 is a deficient number, since it is larger than the sum of its proper divisors (1).

2178649291901 is an equidigital number, since it uses as much as digits as its factorization.

2178649291901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3919104, while the sum is 59.

The spelling of 2178649291901 in words is "two trillion, one hundred seventy-eight billion, six hundred forty-nine million, two hundred ninety-one thousand, nine hundred one".