2195891306521 has 16 divisors (see below), whose sum is σ = 2524859951040. Its totient is φ = 1888751545920.

The previous prime is 2195891306447. The next prime is 2195891306593. The reversal of 2195891306521 is 1256031985912.

It is a cyclic number.

It is not a de Polignac number, because 2195891306521 - 2⁹ = 2195891306009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2195891306321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6634470 + ... + 6957583.

It is an arithmetic number, because the mean of its divisors is an integer number (157803746940).

Almost surely, 2^{2195891306521} is an apocalyptic number.

It is an amenable number.

2195891306521 is a deficient number, since it is larger than the sum of its proper divisors (328968644519).

2195891306521 is a wasteful number, since it uses less digits than its factorization.

2195891306521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13592856.

The product of its (nonzero) digits is 1166400, while the sum is 52.

The spelling of 2195891306521 in words is "two trillion, one hundred ninety-five billion, eight hundred ninety-one million, three hundred six thousand, five hundred twenty-one".